for what positive value of x is d smallest?

Question

y=(x^2)-4

Answer 1

 

x^2 - 4 = 0

 

(x+2)(x-2) = 0

 

THe roots are 2 and -2

 

The min oocurs at their average which is zero

 

the min value is 0^2 - 4 = -4