# Math Help - Derivative

1. ## Derivative

Hello I have a couple questions.

1.) lim x -> 25 sqrt(x) - 5 / x - 25
2.) [1/(x+3)]-1/3/x

these two problems i have not been able to figure out how to solve, since the denominator equals 0 in both but there is an answer. any help works.

thanks

2. Originally Posted by cokeclassic
Hello I have a couple questions.

1.) lim x -> 25 sqrt(x) - 5 / x - 25
2.) [1/(x+3)]-1/3/x

these two problems i have not been able to figure out how to solve, since the denominator equals 0 in both but there is an answer. any help works.
Hint for #1: $\sqrt{x}-5=\frac{x-25}{\sqrt{x}+5}$