SOLUTION: How do you work the following problem: f(x)=x^4-25x^2+144 I know I set the equation to equal zero, but am unsure what to do after that!

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: How do you work the following problem: f(x)=x^4-25x^2+144 I know I set the equation to equal zero, but am unsure what to do after that!      Log On


   

Question 317035: How do you work the following problem:
f(x)=x^4-25x^2+144
I know I set the equation to equal zero, but am unsure what to do after that!
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
factor

0 = (x^2 - 16)(x^ - 9)

and factor again

0 = (x + 4)(x - 4)(x + 3)(x - 3)

x = ±4 , ±3