SOLUTION: Given the polynomial f(x)= x^4 -6x^3 +9x^2 +4x -12 , (I) factorize f(x) completely and hence find the x and y axes intercepts (II) state the x coordinates where the graph of

Algebra.Com
Question 1081854: Given the polynomial f(x)= x^4 -6x^3 +9x^2 +4x -12 ,
(I) factorize f(x) completely and hence find the x and y axes intercepts
(II) state the x coordinates where the graph of y=f(x) cuts the x-axis and where it touches the x-axis
(III) draw a sign diagram for f(x)
(IV) discuss the behaviour of f(x) as x = ∞ and as x = -∞
(V) sketch the graph of y=f(x), using the information obtained above.

Answer by josgarithmetic(39626)   (Show Source): You can put this solution on YOUR website!
Possible roots to try would be -6,-4,-3,-2,-1,1,2,3,4,6,12 (Rational Roots Theorem).
2   |    1   -6   9   4    -12
    |         2   -8  2     12
    |________________________________
        1    -4   1   6     0


3   |    1    -4    1     6
    |
    |          3    -3    -6
    |______________________________

         1    -1   -2     0



Partial factorizing gives .

The quadratic factor breaks into f being



x-intercepts:
-1, 2, 3

y-intercept:
When x=0, y=-12.

Table of Signs:
Check inside each interval on x.
-
(infin, -1]
[-1, 2]
[2, 3]
[3, infinity)
-
You can determine the result in each interval on your own.







RELATED QUESTIONS

Find the x-intercepts and y intercepts for f(x) f(x)... (answered by oscargut)
find the x-intercepts and y-intercepts f(x) = -x^2 +4x +12 need x-intercepts and... (answered by robertb)
Find the vertex, x- intercepts, and y- intercept of... (answered by Menjax)
Find the x-intercepts and the y-intercepts for f(x). f(x)= x^2-9x+9 Thank... (answered by lwsshak3)
given: f(x)=x^2-6x+5 1) write f(x) in standard form 2) find the vertex and x-intercepts (answered by Nate)
Find the x-intercepts and y-intercepts for f(x) f(x)=x^2-9x+2 The x intercepts are?... (answered by ewatrrr)
What are the x intercepts and y intercepts of... (answered by Fombitz)
Given the polynomial F(x) = (1-X)(2x-5)(x+2)^2, sketch the graph of y=f(x), showing all... (answered by josgarithmetic)
Factorize the polynomial {{{ f(x) = x^3 - 7x + 6 }}} completely .Thank-you... (answered by acw1213,ikleyn)