# Calculus

posted by
**Derek**
.

If y= (x^2+20)/(x-4) Find all critical Numbers.

After get f' i got the answer -5/4. What did i do wrong or is that the critical number?

posted by
**Derek**
.

If y= (x^2+20)/(x-4) Find all critical Numbers.

After get f' i got the answer -5/4. What did i do wrong or is that the critical number?