Mathematical induction is a mathematical proof technique. It is essentially used to prove that a statement P(n) holds for every natural number n = 0, 1, 2, 3, . . . ; that is, the overall statement is a sequence of infinitely many cases P(0), P(1), P(2), P(3), . . . . Informal metaphors help to explain this technique, such as falling dominoes or climbing a ladder:
Mathematical induction proves that we can climb as high as we like on a ladder, by proving that we can climb onto the bottom rung (the basis) and that from each rung we can climb up to the next one (the step).
A proof by induction consists of two cases. The first, the base case (or basis), proves the statement for n = 0 without assuming any knowledge of other cases. The second case, the induction step, proves that if the statement holds for any given case n = k, then it must also hold for the next case n = k + 1. These two steps establish that the statement holds for every natural number n. The base case does not necessarily begin with n = 0, but often with n = 1, and possibly with any fixed natural number n = N, establishing the truth of the statement for all natural numbers n ≥ N.
The method can be extended to prove statements about more general well-founded structures, such as trees; this generalization, known as structural induction, is used in mathematical logic and computer science. Mathematical induction in this extended sense is closely related to recursion. Mathematical induction is an inference rule used in formal proofs, and in some form is the foundation of all correctness proofs for computer programs.Although its name may suggest otherwise, mathematical induction should not be confused with inductive reasoning as used in philosophy (see Problem of induction). The mathematical method examines infinitely many cases to prove a general statement, but does so by a finite chain of deductive reasoning involving the variable n, which can take infinitely many values.
Hi,
I've been interested in the science behind electrons/magnetism for quite a while. I've been learning quite a bit from various sources online. However there is one thing that's really nagging me.
Magnetic fields result from moving electrons. That indicates that a permanent magnet has...
Hi,
Can I please ask how the rotating magnetic field (due to the 3 phase ac) is changed? Is it due to the frequency of the ac supply that it can speed up and therefore drag the rotor along due to induction. If it is due to the changing frequency input that mimics a faster rotating magnetic field...
Homework Statement
A current of 50A flows through a copper wire of diameter 0.5 * 10-2m. The magnetic induction on its surface will be:
A)4*102T B)4*10-2 C) 4*10-3 D)none of these
Homework EquationsThe Attempt at a Solution
I just want to verify my solution, as the answer keys are currently...
So, I was studying Maxwell's equations and I don't really understand the last one - Ampere's Law (with Maxwell's extra term added in). The bit I'm not able to understand is the term Maxwell added. How exactly does a changing electric field through a closed loop induce a magnetic field along that...
Hey.
The series $a_n$ is defined by a recursive formula $a_n = a_{n-1} + a_{n-3}$ and its base case is $a_1 = 1 \ a_2 = 2 \ a_3 = 3$.
Prove that every natural number can be written as a sum (of one or more) of different elements of the series $a_n$.
Now, I know that is correct intuitively but...
Homework Statement
What is the necessary area for a generator that produces an emf of ##\mathcal{E} = 150V## when it spins at a ratio of 60 revolutions per second, in a magnetic field of ##B = 0.5 T##?
Homework Equations
##\oint_{c} E \cdot dl = \mathcal{E} = -\frac{d}{dt}\iint_{s} B \cdot dS...
<Moderator's note: Moved from a technical forum and thus no template.>
for every natural n there exists natural k.
and numbers={a0,a1,a2,...ak}∈{0,1}.
so that n=i=0n∑ ai2i
I will assume n=k, i know that if n is even then a0 =0.
so if i assume it is true for n that is Even:
n+1=i=0n+1∑ ai2i...
Hi again. I have one other problem I'm puzzled about.
(a) A sorting algorithm takes one operation to sort an array with one item in it.
Increasing the number of items in the array from n to n + 1 requires at most an
additional 2n + 1 operations. Prove by induction that the number of operations...
Homework Statement
Describe an auto-transformer starter. From the expression for power
input per phase (∝ torque) show that for a turns ratio (n) of √3:1 , for
the auto-transformer:
Homework Equations
Pin (phase) = 3 V I cos∅
I = V/Z
cos∅ = R/Z
T∝I∧2
T∝V∧2
For auto transformer with...
Homework Statement
Prove that 1\cdot1!+2\cdot2!+...+n\cdot n! = (n+1)!-1 whenever n is a positive integer.
Homework EquationsThe Attempt at a Solution
I'm having trouble simplifying towards the end of the proof.
Proof:
Let P(n) be the statement 1\cdot1!+2\cdot2!+...+n\cdot n! = (n+1)!-1...
Homework Statement
Homework Equations
Right Hand Rule
The Attempt at a Solution
I am not understanding why the force is left. I can only figure out that the current in the solenoid is moving clockwise because of the right hand rule. From there, I see that the induced current might be...
Can someone with understanding of proof by induction help with this problem?
Prove by induction that 3 raised to 2n+1 + 2 raised to n-1 is divisible by 7 for all numbers greater than/or equal to 1. How do you do the inductive step?
Homework Statement
Prove by induction that ##\sum\limits_{k=1}^{2n} \frac{1}{k(k+1)} = \frac{2n}{2n+1}##
2. The attempt at a solution
First I showed that it is true for ##n=1## and ##n=2##. Then, assuming it is true for all ##n##, I attempt to show that it is true for ##n+1##...
Hey! :o
For $n\in \mathbb{N}$ let $A_n$ be the real $n\times n$-matrix with the elements \begin{equation*}a_{ij}=\begin{cases}i , &\text{ if } i=j-1 \\ 1, & \text{ if } i=j \\ -j, & \text{ if } i=j+1 \\ 0 , & \text{ otherwise } \end{cases}\end{equation*}
For $n=1, 2, 3$ we get the matrices ...
Homework Statement
Wherein α, β are strings, λ = ∅ = empty string, βr is the shortest suffix of the string β, βl is the longest prefix of the string β, and T* is the set of all strings in the Alphabet T, |α| denotes the length of a string α, and the operator ⋅ (dot) denotes concatenation of...
Homework Statement
Wherein α is a string, λ = ∅ = the empty string, and T* is the set of all strings in the Alphabet T.
Homework Equations
(exp-Recursive-Clause 1) : α0 = λ
(exp-Recursive-Clause 2) : αn+1 = (αn) ⋅ α
The Attempt at a Solution
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This one is proving difficult for me. I...
Homework Statement
Use mathematical induction to prove that (8n − 7n − 1) is divisible by 49 for any n ∈ N.
Correction by mentor for better readability: ##49\,|\,(8^n-7n-1)##
The Attempt at a Solution
We can see that the base case is satisfied here:
n = 1,
8^1-7*1-1 = 0 and 49 | 0 is true...
Hello,
I'm boy who suddenly been strucked by curiosity on how hand crank generator works and i watch and read some of how to create one, specially this one on youtube:
and i want to create one but i don't have a 3D printer, but i saw some alternative but as i do/design my own coil based on...
Hello, I'm having trouble thinking of ways that I can measure the temperature of an object that I am heating using an Induction Heater. A little background: The coil and workpiece will be submerged in liquid, and due to most thermometers being metal it won't work with the induction heater. I'm...
Homework Statement
A straight wire of length 0.20m moves at a steady speed of 3.0m/s at right angles to a magnetic filed of flux density 0.10T. Use Faraday's law to determine the e.m.f. induced across the ends of a wire.
Homework Equations
E= Nd Φ/dt but N=1 so E= dΦ/dt
The Attempt at a...
Hi there, I am new in here, thanks for any reply.
I took same title of a previous closed 3D by pranj5.
As understood main part of the energy absorbed by PV panels goes in reflection and heat.
The heat origins mainly in electrons that are excited but not enough to jump or they jump but they...
Homework Statement
Let ##\phi : G \to H## be a homomorphism. Prove that ##\phi (x^n) = \phi (x)^n## for all ##n \in \mathbb{Z}##
Homework EquationsThe Attempt at a Solution
First, we note that ##\phi (x^0) = \phi(x)^0##. This is because ##1_G \cdot 1_G = 1_G \implies \phi (1_G 1_G) = \phi...
I am struggling to understand the induction proof of the pigeonhole principle in my textbook. The theorem and the proof, from Biggs Discrete Mathematics, is pasted below, and I will explain further (see bold text) what I am having trouble with.
Theorem. Let m be a natural number. Then the...
Homework Statement
There is a magnetic field B=0.02 Tesla and its direction is toward the plane (perpendicular to plane, shown by X X X X X - I'm not sure how to say this direction in English,sorry). we have a copper wire (uniform bar) perpendicular to magnetic field from south to north. we...
Hello all,
I have a question regarding Maxwell's Equations and Faraday's unipolar induction equation.
If we study the case of a cylindrical magnet with a radius of r which is rotating about its axis
with angular velocity w. The electrons within the magnet collide with the moving atoms, causing...
I have a question in my book and it’s confusing me a bit. I tried to search online for similar solved problems but couldn’t succeed. So here it goes:Calculate the induced EMF in a conductor loop when the angle between \vec{A} ~ and~ \vec{B} ~is~ changed ~from ~{0 °}~ to ~{α °} in 1 second...
I need some help with this task, I am stuck.
1. Homework Statement
An aluminium ring is placed on top of an elctromagnet.
a. The electro magnet is connected to AC. What will happen with the aluminium ring? Motivate your answer.
b. What will happen with the ring if the electromagnet is...
Please guide me how to prove the last equation by induction.
Regards!
Conversely, any representation of the form (Zeckendorf's Theorem)
$$n=F_{k_{1}}+F_{k_{2}}+...+F_{k_{r}}, \quad k_{1}\gg k_{2}\gg ... \gg k_{r} \gg 0.$$
Implies that
$$ F_{k_{1}} \leq n < F_{k_{1}+1}, $$
because the largest...
Homework Statement
Hello, good afternoon,
I have a question that's coming up when I'm doing electromagnetic induction exercises. In some exercises they ask me to determine the electromotive force (iee), and when they do the exercise resolution they do it with absolute value. In other...
As I understand Hilbert's omega rule for a first-order proposition P over the natural numbers,
P(0) &P(1) &P(2) &... ⇒ ∀n∈ℕ P(n) :star:
which seems to be the same as ω-consistency. Is there a difference?
Further, the axiom schema of induction has each axiom for a proposition P over the...
Homework Statement
(i) A star-connected, three-phase synchronous induction motor takes a current of 10 amps from a 415 volt supply at unity power factor when supplying a steady load. If the synchronous reactance is 5 ohms/phase and the resistance is negligible, draw the phasor diagram and...
Homework Statement
The correct answer is D
Homework Equations
The Attempt at a Solution
The current is clockwise( in the first picture at least) due to right hand rule.
The magnetic flux is changing, the direction of the induced emf depends on the direction of change (increase or...
before I ask anything I know this has been probably talked about a lot in the past from various different angles, yet when I am searching for answers I cannot find a satisfactory answer that would look at it from the perspective I wish so here is my try.
I've talked with a mentor of mine about...
A 2000-turn solenoid is 2.0 m long and 15 cm in diameter. The solenoid current is increasing at 1.0 kA/s.
(a) Find the current in the 10-cm-diameter wire loop with resistance 5.0 $\varOmega$ lying inside the solenoid and perpendicular to the solenoid axis.
(b) Repeat for a similarly-oriented...
Use the fact that \frac{1}{k} - \frac{1}{k+1} = \frac{1}{k(k+1)} to show that
n
sigma (\frac{1}{k(k+1)}) = 1- \frac{1}{n+1}
r=1
What do I need to do to solve it?
I really want to build a simple but powerful induction heater for hobby blacksmithing.
Metal shaping and the design of the cooling system within the coils are not a problem.
I need help understanding the electronics
Obviously I must first use a transformer as a safety against "backlash" to the...
Prove by mathematical induction that
n
sigma r^3 = n^2(n+1)^2/4
r = 1
so far I have
1
sigma r^3 = 1^2(1+1)^2/2
r=1
1 = 1(4)/2
1 = 4/2
1 = 2
I'm not sure what to do after this for the k+1 case.
We know that primary of a transformer is a coil(mono or multilayer) from a conductive material, usually copper, which have a proper lattice.Inside the lattice is a cloud of free electrons .When in circuit, a voltage is applied at the coil heads.
1.When voltage is applied , do we have a...
Dear community,
For one of the projects which I am currently working on, I want to quantify my three phase AC induction motor in the following ways:
1. Find Torque vs RPM Curve
2.Find Efficiency vs RPM Curve
Now since I don't have the industrial "Torque Sensor" to plot Torque vs RPM curves, I...
Hi folks,
My question relays on the difference of consumption power of a coil when it's on AC and CC regime.
A coild is made of copper wire with air core, aplied on it a CC current of 1 amp, a measure was taked and nottice a 5W of power consumption. Then the power supply is changed to and AC...
I wrote and solved this problem but am having serious doubts about the answer I obtained.
Homework Statement
Two point charges \pm q move along the z-axis with velocity \pm v. If they are at the origin when t=0, what is the electric field magnitude a distance r from the z-axis?
Homework...
Translated from Norwegian high-school physics book:
I wonder how and why does the voltage change on the primary coil when the cookware is removed or boiled over?