Question #c11af Calculus Differentiating Trigonometric Functions Limits Involving Trigonometric Functions 1 Answer Andrea S. Jan 16, 2017 #lim_(x->0) (1-cos(2x))/x^2 = 2# Explanation: Use the identity: #sin^2x = (1-cos(2x))/2# So: #lim_(x->0) (1-cos(2x))/x^2 = lim_(x->0) 2 sin^2x/x^2 = 2 lim_(x->0)(sinx/x)^2 = 2# Answer link Related questions How do you find the limit of inverse trig functions? How do you find limits involving trigonometric functions and infinity? What is the limit #lim_(x->0)sin(x)/x#? What is the limit #lim_(x->0)(cos(x)-1)/x#? What is the limit of #sin(2x)/x^2# as x approaches 0? Question #99ee1 What is the derivative of #2^sin(pi*x)#? What is the derivative of #sin^3x#? Question #eefeb Question #af14f See all questions in Limits Involving Trigonometric Functions Impact of this question 3899 views around the world You can reuse this answer Creative Commons License