Grade 12 Advanced Functions
posted by Rebecca on .
One zero of f(x)=x^3+4x^2+x+c is 3.
a) calculate the value of c.
b)calculate the other zeros.

Ummm, didn't MathMate just do one of these for you? Plug in 3 and evaluate to find c.

Ummmmm, I needed help with the second part

Divide by x+3 and see what you get:
x^3 + 4x^2 + x 6
= (x+3)(x^2 + x  2)
= (x+3)(x+2)(x1)
Got it now? 
what about this question:
Determine the roots algebraically by factoring.
a) x^38x^23x+90=0