Question

lim (x^2) / (cos4x - cos9x) as x->0

Answer 1

what happens when you plug zero into the equation?

Answer 2

Indeterminate form. 0/0

Answer 3

right, so what can we do from here?

Answer 4

L'Hospital Rule.

Answer 5

right, and what do we get from that?

Answer 6

Nvm. L'Hospital wont work in this situation.

Answer 7

why not?

Answer 8

It is still indeterminate. sin(0)=0

Answer 9

right, so we can do L'Hopitals rule again

Answer 10

True. I forgot about it.

Answer 11

after the second derivative you are left with 2 in the numerator, and cosines in the denominator, so you should be good from there

Answer 12

when you do L'Hopitals rule again rather

Answer 13

Do you have an answer?

Answer 14

yes 0.0307692

Answer 15

yes, 0.030769

Answer 16

also 2/65