Question

Given the function:

f(x) = 5x3+8x2−7x−6

Choose 1 of the possible roots and show or describe how you know it is an actual root.

Answer 1

x = 1 is a root of the polynomial

For any polynomial f(x), if x = a is a root then f(a) = 0

f(1) = 5 + 8 - 7 - 6 = 0

Hence x = 1 is a root of f(x)

Answer 2

A=R so,
if x=2, f(2) =15+16-7*2-6=25-14=11

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