Quadratic equation Definition and 252 Threads

  1. M

    Quadratic equation word problem

    1. Problem Barkley runs a canoe-rental business on a small river in Pennsylvania. Currently, the business charges $12 per canoe and they average 36 rentals a day. A study shows that for every $.50 increase in rental price, the business can expect to lose two rentals per day. Find the price...
  2. Matejxx1

    Solving Quadratic Equation with Solutions x1 and x2: How to Calculate x1-3+x2-3?

    1.given the equation a(3x2+2x+1)=4x-6x2-4 with the solutions x1 and x2 a) let a=0 without solving the equation calculate x1-3+x2-3 the correct answer is supposed to be -7/2 Homework Equations x1+x2=-b/a x1*x2=c/a The Attempt at a Solution The first thing I was that I put in...
  3. Saitama

    MHB What Are the Conditions for a Quadratic Equation to Not Meet the X-Axis?

    Problem: If the curve $y=ax^2+2bx+c$, ($a,b,c \,\in\,\mathbb{R},\,a,b,c \neq 0$) never meet the x-axis, then a,b,c can't be in A)Arithmetic Progression B)Geometric Progression C)Harmonic Progression D)All of these Attempt: Since, the curve never meets the x-axis, we have the condition...
  4. M

    Can we visualize the parts of a quadratic equation as area and length?

    consider the equation: ax^2+bx=c imagine that the constant c is divided into to parts: c=Z+Y where ax^2= Z and bx=Y so basically could we say c is part area and part length?? Sorry if the question is not explained better but that's the best way I came up with to describe it.
  5. Y

    What is the correct way to calculate the discriminant in a quadratic equation?

    I know for ##ax^2+bx+c=0##, x=\frac{-b^+_-\sqrt{b^2-4ac}}{2a} Using ##x^2-3x-4=0##, we know it is equal to ##(x+1)(x-4)=0##. So ##x=-1## or ##x=4##. but using the formula: x=\frac{-b^+_-\sqrt{b^2-4ac}}{2a}=\frac{3^+_-\sqrt{9+4}}{2}=\frac{3^+_-\sqrt{13}}{2} I cannot get -1 and 4...
  6. M

    Quadratic equation - how to understand the impact of the middle term?

    Hi, I am trying understand if there is a quick way to figure out the impact of the X term in a quadratic equation. For example, by looking at the following equation, I know that it is a parabola (X^2) ; by looking at 24, I know that it is the y-intercept. However, I don't know what is the...
  7. Saitama

    Quadratic equation and trigonometry

    Homework Statement If the quadratic equation ax2+bx+c=0 has equal roots where a, b and c denote the lengths of the sides opposite to vertices A, B and C of a triangle ABC respectively, then find the sum of integers in the range of $$\left(\frac{\sin A}{\sin C}+\frac{\sin C}{\sin...
  8. B

    How to Solve a Quadratic Equation Using Factorisation?

    Solve the following quadratic equation. Use factorisation if possible. X2 - 4X - 8 = 0 Normally I wouldn't have trouble factorising a quadratic, but I have just been introduced to a new way to do it and I want to use this way to answer the question. Here's how far I get, then I'm unsure what...
  9. K

    Quadratic Equation factorization problem

    Homework Statement In the expression x2 + kx + 12, k is an integer and k < 0. Which of the following is a possible value of k? (A) –13 (B) –12 (C)  –6 (D)   7 Homework Equations I know it uses the a.c method of factorization but don't know how to use it? The Attempt at a...
  10. C

    Finding the Range of k in a Quadratic Equation Problem

    1) Find the range of values of k such that the function f(x) \equiv k(x+2)^2-(x-1)(x-2) never exceeds 12.5. I've missed several stages of the computation because it is quite lengthy. I hope you get the flow of things. My attempt... (k-1)\left[ x + \left( \frac{4k+3}{k-1} \right)x +...
  11. X

    Using 3 Points to Find Quadratic Equation in General Form

    Help! Using 3 Points to Find Quadratic Equation in General Form I have a quadratic equation question that I have to solve, but I can't seem to understand it. The question is: "Using points (1,0);(3,0);(0,-6), find the quadratic formula in General Form (ax^2 + bx + c). My teacher says...
  12. L

    Quadratic equation ball 72km/h

    Homework Statement A ball is thrown at 72km/h speed from top of a building. Building is 125m tall. Homework Equations Distance traveled before it hit the ground is as follows: s = Ut + 0.5 gt^2 The Attempt at a Solution Using quadratic equation: x = -b±b^2 - 4ac / 2a The...
  13. A

    Quadratic Equation Solving: Integer Solutions

    Homework Statement The total number of integers that satisfy the equation x2-4xy+5y2+2y-4=0
  14. J

    MHB No. of real roots of Quadratic equation

    The no. of Real Roots of the equation $\displaystyle \frac{\pi^e}{x-e}+\frac{e^\pi}{x-\pi}+\frac{\pi^{\pi}+e^{e}}{x-\pi-e} = 0$ My try:: Let $\displaystyle f(x) = \frac{\pi^e}{x-e}+\frac{e^\pi}{x-\pi}+\frac{\pi^{\pi}+e^{e}}{x-\pi-e}$ Now we will take a interval $x\in \left(e\;,\pi\right)$...
  15. anemone

    MHB How Do You Solve This Specific Quadratic Equation?

    Solve (m-2)x^2-(m+3)x-2m-1=0.
  16. MarkFL

    MHB Lacey's question at Yahoo Answers regarding a quadratic equation

    Here is the question: Here is a link to the question: Solve the quadratic equation? - Yahoo! Answers I have posted a link there so the OP can find my response.
  17. N

    Solving a Quadratic Equation with Unknown X Coefficient: Homework Help

    Homework Statement Homework Equations x(2x^2 - 5) = -1 The Attempt at a Solution This question has been flung at me without any pre-examples how to solve it. I have only dealt with equations like 2x^2 + 5x - 12 = 0. I know that the equation above should be set to zero, but how...
  18. R

    Find the constant c given quadratic equation F=

    A force F=(cx-3.00x2)i acts on a particle as the particle moves along an x axis, with F in Newtons, x in meters, and c a constant. At x = 0 m, the particle's kinetic energy is 18 J; at x = 5 m, it is 12 J. Find c. F=ma KE=1/2mv2 I guess I don't understand the relationship between force...
  19. W

    Want to solve a quadratic equation

    Homework Statement Actually, it is told by one of my friend. He asked for the answer of this quadratic equation. m^3-m^2+2=0 Homework Equations m^3-m^2+2=0 The Attempt at a Solution But, I think we need one more equation to solve it. Is there any way to solve it by only...
  20. C

    Find the value of x1^6 +x2^6 of this quadratic equation without solving it

    Homework Statement Solve for x_1^6+x_2^6 for the following quadratic equation where x_1 and x_2 are the two real roots and x_1 > x_2, without solving the equation. 25x^2-5\sqrt{76}x+15=0 Homework Equations The Attempt at a Solution I tried factoring it and I got...
  21. B

    Solve Quadratic Equation for x1^2 + x2^2

    Homework Statement If the roots of x^2 - 2x + 4 = 0 are x1 and x2, what is x1^2 + x2^2? Homework Equations The Attempt at a Solution I don't think these questions can be answered by solving for x only cause there will be no real root(complex number). So I found that x1 + x2 =...
  22. P

    How to solve a quadratic equation with a negative value for the variable?

    Homework Statement Solve 4y-y2=x for y. The Attempt at a Solution First I tried using the quadratic equation with a=-1 b=4 c=-x y=(-b±(42-4(-1)(-x))(1/2))/2(-1) That got me this far: y=2±(8-2x)(1/2) Then I checked wolfram and now I am confused . Did I not approach this corectly?
  23. S

    Solving a Quadratic Equation without the Standard Formula

    Homework Statement 3x2-8x-1=0 Homework Equations The Attempt at a Solution So here i attempt to solve the equation...usually the way i go about this is you multiply 3 by -1 you get -3 then i ask myself what multiplies to -3 and adds to -8...after that i am able to solve...
  24. T

    MHB Maximum value of a Quadratic Equation

    Prove that 12x-8-3x^2 can never be greater than 4. How do you prove? Do you find he discriminant? But isn't discriminant for roots only not equations?
  25. Q

    Quadratic equation solving with constraint.

    Homework Statement So I've worked this problem for awhile. Its a several page of math problem with optimization, legrangians, cramers rule, etc to get to this point. All I need to do now is by hand solve this equation for x and y with the constraint. Homework Equations -0.03x^2 + 40x...
  26. A

    MHB Solving a Quadratic Equation with Two Variables

    Solve for $x$: $$4x^2 +4xy - 6y - 9 = 9 $$
  27. B

    Construct quadratic equation using the vertex method

    Homework Statement Folks, I wish to construct a quadratic expression from a graph which has the following 2 coordinates. ##(0,0)## and the vertex ##(\alpha h_e,1)## where ##0<\alpha<1## Homework Equations Using the following ##y(x)=a(x-h)^2+k## The Attempt at a Solution...
  28. O

    How To Find The Factors Of THis Quadratic Equation?

    Hi everyone, Can someone please tell me how to find the factors of the below quadratic equation? 3x^2 - 9x + 4 = 0 I had already tried to find them by using the below method and wasn't able to continue further because of I do not understand. Huygen (3x^2 - 7x + 4) -2x = 0 (3x-4)(x-1)-2x=0
  29. D

    Use algebra to find the x and y intercepts , for a quadratic equation

    Homework Statement Use algebra to find the x-intercepts and y-intercept of The graph of y=-x^2/5+x/5+6 this is a parabola. Homework Equations y=-x^2/5+x/5+6The Attempt at a Solution Find the y-intercept , which is substitute 0=x into the equation to find the answer , done that . The problem...
  30. K

    Graphing a standard quadratic equation?

    How do we graph a quadratic equation in the form ax^2+bx+c =0?, or an equation like , f(x)(or y)= [(x+b/2a)^2 - (D/4a^2)], where D = b^2 - 4ac? or how do we get a parabolic curve intersecting at its roots(of the quadratic equation) in the x axis?
  31. K

    Is expansion necessary for this quadratic equation?

    (x+3)(x-4)(x-2)(x+1) = 24 Can we change it into a quadratic equation without multiplying the expressions under those brackets?
  32. C

    Need to find c in a quadratic equation

    Homework Statement If α and \frac{1}{αα}are the roots of the equation 5x^{2}+13x+k then k will be: a) 5 b) -5 c) 13 d) 1 Homework Equations The Attempt at a Solution I've tried multiplying both the roots to get \frac{c}{a} and adding the roots to get...
  33. J

    General form of the quadratic equation

    I am trying to figure out how the coeffecients in the general second degree equation transform the function as they change through a range of values. I think that d and e are the proportion of x and y are horizontal and vertical shifts, but less sure about a, b, and c. Here is the equation as...
  34. D

    Biomechanics Quadratic Equation problem

    Homework Statement 1. Neglecting the height of release, a ball is thrown vertically upwards at 20 m/s, find: d) time (s) that the projectile is at height 10.5 m. V1 = 20m/s a = -9.81m/s^2 d = 10.5m Homework Equations d = v1*t + 1/2 a(t^2) The Attempt at a Solution...
  35. Saitama

    Quadratic Equation: Finding Values of 'a' Between 2 and 4 with Only One Root

    Homework Statement Find all the values of 'a', so that exactly one root of the equation x2-2ax+a2-1=0, lies between the numbers 2 and 4, and no root is either equal to 2 or equal to 4.Homework Equations The Attempt at a Solution Let f(x)=x2-2ax+a2-1 I tried to visualize the question by graph...
  36. S

    Solution related to certain condition in quadratic equation

    Homework Statement For a constant k, consider the function f(x) = x2 + kx + k2 - 2k - 4 Find the range of k for which f(x) = 0 has one solution between 0 and 1 and the other solution between 1 and 2Homework Equations quadratic formula discriminantThe Attempt at a Solution x2 + kx + k2 - 2k - 4...
  37. R

    Solve Quadratic Equations for x: Mechanics Notes & Error Check

    Hey, I was going through some mechanics notes and came across this quadratic equation to solve for x. In my notes it is supposed to equal 3 however I do not get that result. I am not sure if I am simplifying it wrong or what. I am ending up with 2.12 for the positive value. Please let me...
  38. J

    MHB How Does Trigonometry Affect the Roots of a Quadratic Equation?

    http://www.screencatch.com/screenshots/13354664404923.jpg
  39. C

    Finding the solutions to a quadratic equation with a complex conjugate

    Homework Statement Find all solutions to z^2 + 4conjugate[z] + 4 = 0 where z is a complex number. Homework Equations Alternate form: 4conjugate[z] + z^2 = -4 The Attempt at a Solution I have tried solving this solution using the quadratic formula. However, √b^2 - 4ac = √16 - 4x1x4 = 0...
  40. azizlwl

    Solve Quadratic Equation: √(5x-1) - √x=1

    solve √(5x-1) - √x=1 eq. 1 transpose one of the radicals: √(5x-1)=√x+1 Square: 5x-1=x+2√x+1 Collect terms: 4x-2=2√x or 2x-1=√x Square: 4x^2-4x+1=x, x=1/4 , 1. x=1/4 is not the root by substitution to equation 1. ... My question what makes x =1/4 is not the root, only x=1 is the root.
  41. J

    MHB Roots of $f(x)$ Quadratic Equation: $1x^2+2x+3=0$

    if $f(x)$ be a continuous and assumes only rational values so that $ f(2010) =1. $ then roots of the equation $f(1)x^2 + 2f(2)x + 3f(3) =0$ are
  42. S

    Finding vertex of quadratic equation?

    I have to find the vertex, axis, domain, & range of this quadratic equation: f(x)= -1/2(x+1)^2 -3 I can't remember how to do the vertex. Is it y= -b/2a? Also, I tried factoring the equation, but I think I messed up. I ended up with: f(x)= .25x^2 +.5x-2.75 Thanks
  43. T

    Understanding the Properties of Imaginary Cube Roots of Unity

    Homework Statement Let the roots of x2 + x + 1 = 0 be \alpha and \beta, form a quadratic equation with roots: (i) \alpha2, \beta2; and (ii) \frac{1}{\alpha}, \frac{1}{\beta}.The attempt at a solution sum of roots = \alpha + \beta = -1 product of roots = \alpha\beta = 1 (i) sum of roots =...
  44. C

    Finding transformations and base function of quadratic equation.

    Homework Statement For each of the following, identify the base function and describe the transformation(s): f(x)=-4(3x)^2 + 5 Homework Equations f(x) = -4(3x)^2 + 5 The Attempt at a Solution Alright so my attempt at figuring out the requested answers are: Base function = x^2...
  45. K

    How do I slove this quadratic equation?

    Homework Statement I'm studying for the GMAT and the study materials do not include how to solve this equation. I need to know how to solve it without a calculator. Homework Equations If 2^x - 2^x-2 = 3(2^13), what is the value of X? The Attempt at a Solution The answer key says...
  46. R

    Rotation of axes to Eliminate the xy-term in a quadratic equation

    Homework Statement Rotation of axes to Eliminate the xy-term in a quadratic equation 3x^2 - 10xy + 3y^2 + 16 √2x - 32 = 0 2. The attempt at a solution I do not know the method that should be taken to solve this sort of question. That is what I am looking for. If anyone can point me...
  47. H

    Solution to quadratic equation doesn't look right

    Homework Statement Homework Equations distance = rate * time The Attempt at a Solution So the speed of the ball I have as: [t = time] 5 + 32t Which I believe makes sense because the ball is initially traveling @ 5 ft/sec, and after 1 second, the ball is traveling 37...
  48. N

    What are the Solutions to a Complex Quadratic Equation?

    Homework Statement Hello! z^2 - (7+2i)z + (12+8i) = 0 The Attempt at a Solution I used the quadratic equation and got: z = (7+2i)/2 +- sqrt( -3/4 - i) r = 5/4, and the argument is Theta = arctan(-1/-3/4) = 0.927 925 - Pi (since x < 0 and y < 0, right?) Then, I know that z =...
  49. PrincePhoenix

    What is the range of a rational function?

    Homework Statement The following equation defines a rational function.Find its Range f(x) = x2/(x-1) The attempt at a solution Let y = x2/(x-1) =>y(x-1) = x2 =>xy-y = x2 =>x2-xy+y = 0 comparing with the general form of quadratic equation ax2+bx+c = 0, a=1, b=-y, c=y...
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