Question

find the limit as x approaches 0 of sin5x/sin4x

Answer 1

u know x--->0 sinx/x =1

Answer 2

yes

Answer 3

so use f(x)---->0 sin(f(x) )/ (f(x)) =1

Answer 4

so x----->0 sin(5x) / (5x) =1

Answer 5

and x----->0 sin(4x) / (4x) =1

Answer 6

yes i got that far and then

Answer 7

x approaches 0 of (sin5x/5x) / (sin4x/4x) * (5/4)

Answer 8

I believe you can also use L'Hopital's rule on this. Just take f'(x)/g'(x) and your limit should go to 5/4 since cos(5x) and cos(4x) both go to 1 as x--->0

Answer 9

ok thank you both I got that answer but I wasn't sure if it was right. =)