Ask questions and get helpful responses.
Ask a New Question
  1. Questions

MATHS

two zeros of cubic polynomial ax^3+3x^2-bx-6 are -1 and -2. find the third zero and values of a and b

  1. 👍
  2. 👎
  3. 👁
  4. ℹ️
  5. 🚩
JASLEEN

  1. if x=-1, then -a + 3 + b - 6 = 0
    a - b = -3
    if x=-2, then -8a + 12 + 2b - 6 = 0
    8a - 2b = 6
    4a - b = 3
    subtract them:
    3a = 6
    a = 2
    in a-b=-3
    2-b = -3
    b = 5

    so expression is
    2x^3 + 3x^2 - 5x - 6

    which is (x+1)(x+2)( ?x + ?)
    by common sense, the last bracket must be
    (2x -3)

    so the third root is x=3/2

    check:
    (x+1)(x+2)(2x-3)
    = (x^2 + 3x + 2)(2x-3)
    = 2x^3 - 3x^2 + 6x^2 - 9x + 4x - 6
    = 2x^3 + 3x^2 - 5x - 6 , all is good

    1. 👍
    2. 👎
    3. ℹ️
    4. 🚩
    Reiny

Respond to this Question

First Name

Your Response

Similar Questions

  1. algebra

    Write the polynomial in standard form. Then name the polynomial based on its degree and number of terms. 2 – 11x^2 – 8x + 6x^2 A. –5x^2 – 8x + 2; quadratic trinomial B. –5x^2 – 8x; quadratic binomial C. –6x^2 – 8x

  2. Precalculus

    Suppose that a polynomial function of degree 4 with rational coefficients has i and (-3 + square root of 3)as zeros find the other zeros

  3. algebra

    form a polynomial f(x) with real coefficients having the given degree and zeros. Degree 4; zeros:-3 +5i; 2 multiplicity 2 enter the polynomial f(x)=a(?)

  4. Math

    Which of the following statements about a polynomial function is false? 1) A polynomial function of degree n has at most n turning points. 2) A polynomial function of degree n may have up to n distinct zeros. 3) A polynomial

  1. maths

    alpha beta gamma are zeros of cubic polynomial x^3-12x^2+44x+c. if alpha beta gamma are in Ap find the value of c class 10

  2. Algebra 2 help please :)

    What is a cubic polynomial function in standard form with zeros 1, –2, and 2? Use synthetic division to find P(3) for P(x) = x^4 – 6x^3 – 4x^2 – 6x – 2. Divide 3x^3 + 3x^2 + 2x – 2 by x + 3 using long division. Divide

  3. Algebra

    Information is given about a polynomial f(x) whose coefficients are real numbers. Find the remaining zeros of f. Degree 5; zeros: 9, 3+5i, -9i

  4. Math

    Q.1)If one zero of the polynomial 3x2-kx-2 is 2 find the other zero.allso find the value of k. Q.2)If sum of the zeroes of the polynomial x2-x-k(2x-1) is 0,find the value of k Q.3)If 2 and 3 are the zeroes of the polynomial

  1. Algebra

    Suppose that a polynomial function of degree 5 with rational coefficients has​ 6, −2+4i, 4−sqrt2 as zeros. Find the other zeros. Thank you!

  2. rational zeros theorem

    Use the rational zeros theorem to find all the real zeros of the polynomial function. Use the zeros to factor f over the real numbers. f(x)=25x^4+26x^3+126x^2+130x+5 Find the real zeros x= Use the real zeros to factor f f(x)=

  3. College Algebra

    OOPS I got the zeros wrong in the last post...please show work. Find a polynomial of the specified degree that has the given zeros Degree 4: zeros -2,0,2,4

  4. ALG PAPFUTP1

    1. Which equation is best represented by the graph? a. y= (x+3)(x+1)(x-1) b. y= (x-3)(x+1)(x-1) c. y= -(x-3)(x+1)(x-1) d. y= (3-x)(x+1)(x-1) 2. Shown below is the graph of y=x^3-3x^2-6x+8. What are the apparent zeros of the

Still need help? You can ask a new question.