SOLUTION: {{{ F(x)=x^4 + 15x^2 - 16 }}} . How do I find the zeros ?

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: {{{ F(x)=x^4 + 15x^2 - 16 }}} . How do I find the zeros ?      Log On


   

Question 543043: +F%28x%29=x%5E4+%2B+15x%5E2+-+16+ . How do I find the zeros ?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
+F%28x%29=x%5E4+%2B+15x%5E2+-+16+ . How do I find the zeros ?
:
x^4 + 15x^2 - 16 = 0
Can be factored to
(x^2 + 16)(x^2 - 1) = 0
which is
x^2 = -16
x = sqrt%28-16%29, not a real solution
:
Only two real solutions
x^2 = 1
x = +/- sqrt%281%29
x = +1
and
x = -1