Question

limit of 3(1-cosx)/x as x approaches 0

Answer 1

do u know the l hopital rule?

Answer 2

have u tried it yet?

Answer 3

i am gong to make a guess that you have not got to derivatives yet, let alone l'hopital's rule
am i right?

Answer 4

Yeah you're right

Answer 5

then here is what you need to know:
\[\lim_{x\to 0}\frac{\cos(x)-1}{x}=0\]

Answer 6

the 3 out front is not important because \(3\times 0=0\)

Answer 7

Well alright. Thanks!

Answer 8

the other one you need to know is
\[\lim_{x\to 0}\frac{\sin(x)}{x}=1\]
you will need these to find the derivatives of sine and cosine
they are usually proved in a not very convincing way by geometry and an appeal to something called the "squeeze theorem" but you don't need to prove it, just try to remember it

Answer 9

yw