# Find the limit as f(x) approaches 0

• Oct 13th 2009, 06:26 AM
frozenflames
Find the limit as f(x) approaches 0
lim as x --> 0

$[sin^2 (2x)]/x^2$
• Oct 13th 2009, 06:29 AM
roshanhero
Use L'hospital rule
• Oct 13th 2009, 06:30 AM
frozenflames
Quote:

Originally Posted by roshanhero
Use L'hospital rule

i know the answer is 4 but i don't know how to get there...or how to use that rule
• Oct 13th 2009, 06:39 AM
roshanhero
Can u differentiate sin^2(x) and x^2
• Oct 13th 2009, 06:40 AM
frozenflames
Quote:

Originally Posted by roshanhero
Can u differentiate sin^2(x) and x^2

actually no i get it now.

i have to multiply top and bottom by 2. that results in a special limit for sin.

(2sin2x/2x)^2
=(2)^2
=4
• Oct 13th 2009, 06:48 AM
roshanhero
yeap.............