Negative Definition and 1000 Threads

In mathematics, a negative number represents an opposite. In the real number system, a negative number is a number that is less than zero. Negative numbers are often used to represent the magnitude of a loss or deficiency. A debt that is owed may be thought of as a negative asset, a decrease in some quantity may be thought of as a negative increase. If a quantity, such as the charge on an electron, may have either of two opposite senses, then one may choose to distinguish between those senses—perhaps arbitrarily—as positive and negative. Negative numbers are used to describe values on a scale that goes below zero, such as the Celsius and Fahrenheit scales for temperature. The laws of arithmetic for negative numbers ensure that the common-sense idea of an opposite is reflected in arithmetic. For example, −(−3) = 3 because the opposite of an opposite is the original value.
Negative numbers are usually written with a minus sign in front. For example, −3 represents a negative quantity with a magnitude of three, and is pronounced "minus three" or "negative three". To help tell the difference between a subtraction operation and a negative number, occasionally the negative sign is placed slightly higher than the minus sign (as a superscript). Conversely, a number that is greater than zero is called positive; zero is usually (but not always) thought of as neither positive nor negative. The positivity of a number may be emphasized by placing a plus sign before it, e.g. +3. In general, the negativity or positivity of a number is referred to as its sign.
Every real number other than zero is either positive or negative. The non-negative whole numbers are referred to as natural numbers (i.e., 0, 1, 2, 3...), while the positive and negative whole numbers (together with zero) are referred to as integers. (Some definitions of the natural numbers exclude zero.)
In bookkeeping, amounts owed are often represented by red numbers, or a number in parentheses, as an alternative notation to represent negative numbers.
Negative numbers appeared for the first time in history in the Nine Chapters on the Mathematical Art, which in its present form dates from the period of the Chinese Han Dynasty (202 BC – AD 220), but may well contain much older material. Liu Hui (c. 3rd century) established rules for adding and subtracting negative numbers. By the 7th century, Indian mathematicians such as Brahmagupta were describing the use of negative numbers. Islamic mathematicians further developed the rules of subtracting and multiplying negative numbers and solved problems with negative coefficients. Prior to the concept of negative numbers, mathematicians such as Diophantus considered negative solutions to problems "false" and equations requiring negative solutions were described as absurd. Western mathematicians like Leibniz (1646–1716) held that negative numbers were invalid, but still used them in calculations.

View More On Wikipedia.org
  1. Benjamin_harsh

    Explain why a negative sign is used before the 750(1.25)?

    ##R_{X} = \sum F_{X}## ##R_{X} = 750.sin 60^{0} + 250## ##R_{X} = 899.52 N## to the right. ##R_{y} = \sum F_{y}## ##R_{y} = 750.cos 60^{0} - 1250## ##R_{y} = - 875 N## ##R_{y} = 875 N ## downward ##R = \sqrt {R_{x}^{2} + R_{y}^{2}}## ##R = 1254.89 N## ## tan θ_{X} = \large \frac...
  2. Hawkingo

    Why there is a negative sign in the formula of calculating work done?

    $$W = - \int _ { a } ^ { b } \vec { F } \cdot d \vec { r }$$ ( The Force here is referring to the applied force, When moving a positive charge towards another positive charge(stationary) / field In this formula why there is a negative sign in the formula? I am not asking the sign of the total...
  3. Benjamin_harsh

    How negative sign appeared out of nowhere?

    I have to find resultant for this couples: My sir resolved given forces into components like this: He considered Fx couples for sides 3,4,5 triangles: He wrote resultant force for this above diagram: ##\Sigma F_x = \textbf{-}2*\frac{4F}{5}##
  4. Hawkingo

    Why the work done is negative when bringing 2 opposite charges together?

    we know that if the applied force is in the direction of the displacement then work done is positive.But in case of bringing 2 opposite charges from infinite to a certain distance,the work done is negative even the force and the displacement of the charge is in the same direction. From...
  5. P

    Solving Equations for t': Negative Time Confusion

    Equations: Question: Using the equation for t' I got the answer -0.00000499756s (Wrong anyway) As we know the values: v = 0.67c m/s x = 3900 m t = 0.000005 s Also how can time be negative? Does this mean that event 2 happened before the first event when t = 0?
  6. SamRoss

    I Why is the Laplace transform unchanged when t is replaced with -t?

    In Mathematical Methods in the Physical Sciences by Mary Boas, the author defines the Laplace transform as... $${L(f)=}\int_0^\infty{f(t)}e^{-pt}{dt=F(p)}$$ The author then states that "...since we integrate from 0 to ##\infty##, ##{L(f)}## is the same no matter how ##{f(t)}## is defined for...
  7. C

    Understanding Negative Feedback Systems: Equations, Dynamics, and Activation

    We express such equations by $$\frac{dx}{dt} = \beta - \gamma \cdot x$$, t denotes the time. In this case, γ depends on x, thus the dynamic equation should probably be: $$\frac{dx}{dt} = \beta - \gamma(x) \cdot x$$ 1. Setting the equation to 0 leads to two different cases: If x < K: xST = γlow...
  8. C

    A Negative Hydrogen Ions in Cyclotrons and elsewhere

    Negative Hydrogen Ions in Cyclotrons and elsewhere I was vaguely aware that negative hydrogen ions are used in some cyclotrons and this improves beam current. I've been thinking about this recently after noting that hydrogen is actually quite electronegative in comparison to most metals (just...
  9. W

    Root Locus of Negative Feedback System

    From my understanding, the root locus is only concerned with open loop gain. I figured this means you would ignore the negative feedback loop and calculate the root locus from just the plant's function Workings: zeros: -1 poles: 0, -2, -2, relative degree = 2 => 90-degree asymptotes meeting...
  10. S

    Help with negative charges in an electric field.

    How can a negative charge move towards a position of a higher electric potential from lower potential but lose electric potential energy?From my understanding, I understand that for a positive charge, it must lose potential energy from the electric field as work is done by the electric force in...
  11. M

    I Understanding Negative Inclination Orbits in Space Science

    What does it mean for an orbit to have a negative inclination? is it equivalent to an orbit with the same positive inclination but a shift in the node \Omega by \pi ?
  12. A

    Ampere's Law: Double Negative Line Integral Help

    Hi all, I’m having some trouble finding a minus sign in a standard calculation I have been doing. I am trying to show that if there is no enclosed current around the example loop in the enclosed jpeg, the four piecewise paths add up to zero (for the line integral part of Amp’s law). For this...
  13. iVenky

    MOS capacitance when Vgs is negative

    I have a question on what happens to MOS capacitance Cgs+Cgd, when Vgs goes negative in the NMOS shown. I see that when Vgs goes negative, the channel is full of holes because of p- substrate, which means we see the Cox capacitance (without any other capacitance in series), but I am not sure if...
  14. R

    Exponential function with negative base

    Homework Statement -2^x = y Homework EquationsThe Attempt at a Solution When I plug this function in my graphing calculator, it appears to be 2^x reflected across the x axis. This doesn't make sense to me. For example, for x values of 1 and 2, the value of y is not on the same half of the...
  15. iVenky

    Solving Charge Across Plates of a Capacitor w/ Negative Ions

    Homework Statement I have a material placed between parallel plates depleted of free electrons and contain negative ions. What would happen to the charge stored across the plates? Would it still be similar to placing a capacitor with a di-electric constant between them? Homework Equations Q=CV...
  16. Arman777

    I Why does an Empty Universe have to obey Negative Curvature?

    Its stated that empty universe should have a hyperbolic geometry (Milne Universe) but I don't understand how its possible. $$H^2=\frac {8\pi G\epsilon} {3c^2}-\frac {\kappa c^2} {R^2a^2(t)}$$For an empty universe when we set ##\epsilon=0## we get $$H^2=\frac {-\kappa c^2} {a^2(t)}$$...
  17. C

    I Detect Negative Mass Matter: Experiments in Solar System

    How could we detect negative mass matter? The only proposal I've ever heard of is that we could detect there's a cutoff frequency in the gravitational waves we receive, due to attenuation of those lower frequency waves by negative matter. Are there more experiments that could be conducted...
  18. A

    I Negative Mass & White Holes: Does It Create?

    does somebody with a negative mass create a white hole instead of a black hole because of its anti gravity property.
  19. C

    I Is there a mechanism for creation of negative energy density

    Excuse me for bad wording in the title, but there is only so much you can do with the character limit. So, has there ever been a proposal for a mechanism through which negative energy density could be created? Or the only possibility considered so far was that it would have been created in the...
  20. L

    Exploring the Negative Effects of Hysteresis in Metals and Electrical Systems

    what are the negative effect of hystersis in metals or negative effects of magnetic hystersis for electrical hystersi over heatin in wires causing low energy transfer and effency
  21. WeiShan Ng

    [Fluid Mechanics] Negative sign on the viscous work term

    Homework Statement I am revising on the derivation of the differential equation of energy (White's Fluid Mechanics 7th ed) and I'm having trouble understanding the sign convention used in the viscous work term. The textbook first define an elemental control volume and list out the inlet...
  22. KarlM

    A Dark matter and energy explained by negative mass

    Any thoughts on this paper? https://arxiv.org/abs/1712.07962
  23. Krushnaraj Pandya

    Can a direction cosine squared be negative?

    Homework Statement A line makes some angle T with each of x and z axis, and angle U with y-axis so that sin^2(U)=3sin^2(T). Homework Equations 2cos^2(T)+cos^2(U)=1 ...(i) cos^2(x)+sin^2(x)=1 The Attempt at a Solution Using the above two eqns. give us the correct value for cos^2(T) which is 3/5...
  24. T

    Do vacuum Ironing boards cause negative pressure in my Space

    Hey, I'm designing an HVAC system for a laundry building. I have vacuum equipment (Vacuum press and Vacuum Ironing boards ) in the space which have a vacuum outlet the is taken outside the building through individual ducts. When all machines are operational, 877 l/s of hot air and moisture would...
  25. opus

    Right-Endpoint-Sum is negative? Approximating Areas

    Homework Statement Find ##R_4## for ##g(x)=cos(πx)## on ##[0,1]## Homework EquationsThe Attempt at a Solution (i) Since we want ##n=4## even sub intervals between ##x=0## and ##x=1##, intervals are ##[0, \frac{π}{4}]##, ##[\frac{π}{4}, \frac{π}{2}]##, ##[\frac{π}{2}, \frac{3π}{4}]##...
  26. snoopies622

    B Does Negative Mass Have Physical Significance in Modern Theories?

    Yesterday I wrote a simple computer simulation for a spring which, when released, sends two masses flying in opposite directions, and views the event from two different reference frames. My goal was just to convince myself that relativistic mechanics is self-consistent and indeed every time I...
  27. M

    Proving Negative Infinity Divergence of (5-n^2)/(3n+1)

    Homework Statement prove (5-n^2)/(3n+1) diverges to negative infinity as n approaches infinity Homework Equations For all M>0 there exists an N in the natural numbers such that for all n >= N, x_n <= -M The Attempt at a Solution Let M be an element of the field of the real numbers. Let N in...
  28. YMMMA

    Magnetic force direction on a positive and negative charges

    Homework Statement The question askes about the path of the electron. I need to know if I am doing it correctly whether it was asked for a proton or an electron. Homework Equations F=QV⊥Bsinθ The Attempt at a Solution I answered it C. Because it is an electron, I used my left hand. My thumb...
  29. matqkks

    I Can we have modulo a negative number?

    Why can't we have modulo negative number? I have never seen this.
  30. M

    How to know 'the displacement of a particle is 'negative'?

    Homework Statement If x1 and x2 are the initial and the final position vectors of particle respectively. Then, displacement of the particle is delta x = x2 - x1 But my question is how to know that the displacement is negtivive and its direaction? (could you provide a practical example so that I...
  31. Jerry Z

    Homework help: Uncertainty with negative power

    Question: A distance R is measured to be 3.400 ± 0.007m. What is the absolute uncertainty in R^−2? Attempted solution: Relative uncertainty: 2* (0.007/3.4) = 4.11E-3; R^-2 = 3.4^-2 = 0.0865 m^-2; Absolute uncertainty = R^-2 * relative = 0.0865 * 4.11E-3 = 3E-4 m^-2; Any help would be greatly...
  32. HCverma

    Where does the negative charge come from in H2S?

    If we split H2S we get H2S = 2H+ + S2- Where does the negative charge come from in H2S? Do we get 2- charge from the 2H atoms (now two protons after losing the electrons), I mean 2H+ or 2 protons get separated leaving behind the two electrons on S?
  33. HCverma

    In coordinate bond, why doesn't the H^+ atom get a negative charge?

    In a coordinate bond, why H^+ atom don't get the negative charge? as an example [NH4]^+ If we split [NH4]^+, we get NH3 + H^+. In NH3, N and 3H atoms have completed their octet and H^+ accepts the lone pair of electrons from the N, As we know H^+ has no any electrons but a proton. If it receives...
  34. Krushnaraj Pandya

    Area under a curve-positive and negative area cancellation

    Homework Statement So this is a problem I've been facing while finding the area under some curves, for example finding the area bounded by sinx and cosx between pi/4 and 5pi/4. integrating sinx-cosx with these limits would result in the positive and negative areas cancelling out, how do I get...
  35. enter

    Negative Velocity or Acceleration

    So, velocity is a vector, right? And vectors can't have negative magnitudes, right? Then why is leftward velocity considered negative in 1D kinematics? It just seems off to me. Same with acceleration, and pretty much _every vector in all of physics._
  36. opus

    B Why is pH a negative logarithm?

    I'm going over applications of logarithms in my College Algebra class and I'm at a part where it talks about pH scales, and it shows the pH concentration of a substance to be the negative logarithm of hydronium ions. I want to know why the logarithm is negative, so I googled it and the answers...
  37. Demystifier

    A Negative cosmological constant from string theory

    Allegedly, string theory (in it's simplest form) predicts that cosmological constant must be negative (or zero). Can someone explain where does this result come from? A reference would also be welcome.
  38. Mr Davis 97

    I Whether root should be positive or negative

    I'm trying to find ##\sin (\arccos x)##. I let ##\theta = \arccos x## and then use ##\sin ^2 \theta + \cos ^2 \theta = 1##, I get ##\sin (\arccos x) = \pm \sqrt{1 - x^2}##. I'm not sure whether to take the positive or negative root. On Wolfram Alpha is shows that the result is the positive root...
  39. Islam Hassan

    I Hawking Radiation and the Negative Energy Particle

    The following from Wiki re Hawking Radiation:“... vacuum fluctuations cause a particle–antiparticle pair to appear close to the event horizon of a black hole. One of the pair falls into the black hole while the other escapes. In order to preserve total energy, the particle that fell into the...
  40. lc99

    Why is Work Negative in PV diagram?

    Homework Statement Homework EquationsThe Attempt at a Solution Was wonder how the isotherm is negative? Is it because it is going counterclockwise (the arrows)? If this is the case, i don't see why a-c would be positive work... I'm just confused on whether work should be positive or...
  41. Ahmed Abdalla

    Negative absorption coefficient in muon absorption?

    Homework Statement I am conducting an experiment where I am interested in finding the absorption coefficient of different materials as muons pass through them. My data was all well until I realized more muons were measured AFTER they passed through one of the materials, which makes no sense...
  42. T

    Negative Heat Sink thermal resistance

    I'm currently developing a heat sink for a product that produces up to 150 W max power dissipation. I'm currently getting a negative thermal resistance for the heat sink. I don't think that is possible.. I'm not sure how to move on at this point to properly design a heat sink to meet the heat...
  43. Biker

    Turning the refraction formula into reflection: Negative index

    In refraction of spherical surfaces, We derived the formula to be: ## u_2 L^{'} = u_1 L + (u_2 - u_1) R## Where ##L^{'}## is the reciprocal of the distance of the image. ##L## is the reciprocal of the distance of the object. ##u_2## is the refractive index of the medium that the light ray is...
  44. EastWindBreaks

    What happened to the negative sign?

    Homework Statement Homework EquationsThe Attempt at a Solution I thought it would become d/dx(-kAc*dT/dx)+hp(T-T)=0 instead of where the equation in the red box? I don't see how are they equivalent [/B]
  45. Murphy.T

    Potential Energy of an Electron near a negative source charge

    If an electron starts from rest 85.0 cm from a negative fixed source charge of -0.135 micro coulombs we use the equation ke final - ke intial + pe final - pe intial. In solving you use ke = pe which appears to cancel out the inital kinetic and potential energy but how can the initial potential...
  46. C

    Understanding the Ideal Op-Amp Negative Feedback Loop

    Homework Statement Hi, Here is what I know about the Ideal Op-Amp. - The open loop voltage gain is infinite - The output voltage is given by the following $$v_o = A(v_+ - v_-)$$ - Only with a negative feedback loop is $$ v_+ = v_-$$ My query is with regards to the negative feedback loop...
  47. Paddyster

    How to create diffraction gratings from negative film

    Hi, I recently tried to create diffraction gratings using the negative film of a disposable camera. I designed them so the 'slits' were black and the rest was white so on the negative film the slits would be transparent and the rest would be opaque. It didn't work however. Does anybody have any...
  48. S

    Negative square amplitude for a decay process

    Homework Statement I'm trying to compute the square amplitude ## |\mathcal{M}|^2 ## for a decay process in which a Majorana fermion, call it ## \chi_2 ##, decays into another Majorana fermion, ## \chi_1 ##, and a vector boson denoted by ## A^{\mu} ##. The model is such that the mass of the two...
Back
Top