Question

lim x-->0 1 - cos9x / sin 9x

Answer 1

you get 0/0 which is indeterminate.

you need to use what is called L'Hopitals rule where you can differentiate the top and bottom and the limit will be the same

--> 9sin(9x)/9cos(9x) = tan(9x)

lim x->0 tan(9x) = 0

Answer 2

thank you! can you help me with another one?

Answer 3

lim x→0 cos 9x − cos^2 *9x / 9x

Answer 4

same thing, take derivative of both top and bottom functions

Answer 5

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