Use 1' Hopital's Rule t find the limit. SHOW WORK Lim cos x-1 /2x(squared) is 0/0 form.
Whenever you have a limit of indeterminate form of type 0/0
just differentiate the top and the bottom separately.
Now you take the limit of f'(x)/g'(x)
NOTE: Here we differentiated only once, but sometimes you have to differentiate multiple times in order to get the limit.