# Math Help - [SOLVED] trig limits

1. ## [SOLVED] trig limits

Hi I am looking for the limit..
Lim x approach k sin(x-k)/(x^2-k^2)
I tried LHopitals Rule and got f (x)=cos2k-cos2k
and g (x) =2k-2k
which is (cos2k-cos2k)/(2k-2k)
answer is suppose to be 1/2k.

What did I miss?

2. Originally Posted by Neverquit
Hi I am looking for the limit..
Lim x approach k sin(x-k)/(x^2-k^2)
I tried LHospitals Rule and got f (x)=cos2k-cos2k
and g (x) =2k-2k
which is (cos2k-cos2k)/(2k-2k)
answer is suppose to be 1/2k.

What did I miss?
Don't do that L'hopital stuff....

Remember that $\frac{\sin(x)}{x}\overset{x\to0}{\to}1$ and $\frac{\sin(x-k)}{x^2-k^2}=\frac{\sin(x-k)}{x-k}\cdot\frac{1}{x+k}$..

3. ## trig limits

Hi I got it now