Question

Find the zeros of the function:

f(x) x^2-4x√5 +19

Answer 1

I don't understand how to solve it with the 4x√5. Do I have to get rid of it?

Answer 2

x^2-4x√5 +19=0
implies x^2-2x.2√5+(2√5)^2+19-(2√5)^2=0
implies (x-2√5)^2=1
or, x-2√5=1,-1
or, x=1+2√5,-1+2√5

Answer 3

Okay, thank you!!

Answer 4

Actually, I can't really tell what you're writing. Can you write it again? I'm sorry...