- #1
tjohn101
- 93
- 0
Homework Statement
Find all critical numbers of:
g(x)= sqrt(x2-4)
and
f(x)= (1)/(x2-9)
Homework Equations
n/a
The Attempt at a Solution
1) sqrt(x2-4)
simplified to x(x-2)(x+2)-1/2 (please check)
and got zeroes as x=0, x=2, x=-2
and I got confused because if you do g(2) and g(-2) it equals zero. For some reason I can't tell if they are defined or undefined. x=0 works, so that is a critical number. The other two are throwing me off.
2) (1)/(x2-9)
zeroes were x=-3, x=3, x=0. Plugging 3 and -3 back into f(x) gave me undefined, so I'm pretty sure 0 is the only critical number.
If you could please check the second and help with the first that would be great. Thank you