Proof
- (1 − cos x)/x = x × (1 − cos x)/x².
- The second factor tends to ½ and x tends to 0, so the limit is 0 × ½ = 0.
Standard limits
Questions students ask
What is the limit of (1 − cos x) / x as x tends to 0?
0.
How do you prove lim x→0 (1 − cos x) / x = 0?
(1 − cos x)/x = x × (1 − cos x)/x². The second factor tends to ½ and x tends to 0, so the limit is 0 × ½ = 0.