Question

limit as x goes to 0:
(cos(4x)-1)/5x

Answer 1

I pulled out a -1 for the numerator

Answer 2

This one is tricky because again if you put in x goes to 0 you get 0/0
I would recommend using L'hopital's rule, if you are willing to give it a shot

Answer 3

use l'Hôpital's rule ... differentiate

Answer 4

=lim (-4sin4x)/5 = 0

Answer 5

we haven't been taught that yet _ sorry guys and thanks for the patience ! using pinching theorem at the moment

Answer 6

Yeah, you need to use l'Hopital's rule to see which one is approaching 0 faster.

Answer 7

can you not pull out -1(1+cos(4x) and solve from there?

Answer 8

If you pull out a -1 you would have -1(1 - cos(4x))

Answer 9

Which has the same trouble.

Answer 10

check out my attachment
it is with l'hospital's rule

Answer 11

without*

Answer 12

you don't need l'hospital eventhough he is a great guy

Answer 13

thank you so much!