Question

Find the domain of f for each of the following functions. If you need to enter - or , enter -INFINITY or INFINITY.

f(x)= sqrt(64-x^2)

Answer 1

you have to make sure that
\[64-x^2\geq 0\]
the graph of
\[y=64-x^2\] is a parabola facing down, therefore it will be positive between the zeros and negative outside (think of the picture). the zeros are -8 and 8 so it is positive between -8 and 8
your answer is
\[[-8,8]\]

Answer 2

Oh okay, I understand now. Thank you!