Question

f(x)= 4x^2 -3
What is the domain if the range is 1<=f(x)<=13?

Is the domain -2<=x<=2, 1<=x<=2, or -2<=x<=-1? And why?

Answer 1

1<=4x^2-3<=13
4<=4x^2<=16
1<=x^2<=4
1<= x <=2

Answer 2

and -2<=x<=-1

Answer 3

In real numbers, 1<=x<=2 U -2<=x<=-1

Answer 4

Makes sense