Question

Find the zeros simplify all irrational and complex solutions

f(x)=x^4-11x^2-80

Answer 1

Explanation:

f(x)=x^4-11x^2-80=x^4-16x^2+5x^2-80

=x²(x²-16)+5(x²-16)

=(x²-16)(x²+5)

=(x-4)(x+4)[x²-(-5)]

=(x-4)(x+4)[x^2-(5i²)]

=(x-4)(x+4)(x-√5 i)(x+√5 i)

so zeros are 4,-4,√5 i,-√5 i