proof for the derivative of sin(x) is cos(x) (5 marks)

let f(x)=sin x f'(x) lim h-> 0 = ( sin(x+h) - sin(x))/h. f'(x) lim h-> 0 =( sin(x)cos(h) + cos(x)sin(h) - sin(x))/ h. f'(x) lim h-> 0=(sin(x)(cos(h)-1)/h + cos(x) (sin(h))/h. then as h tends to zero. (cos(h)-1)/h=0 and sin(h)/h =1. f'(x)= cos(x) QED

NP
Answered by Nicola P. Maths tutor

3800 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

y = 4(x^3) + 7x ... Find dy/dx


A curve has parametric equations -> x = 2cos(2t), y = 6sin(t). Find the gradient of the curve at t = π/3.


Integrate y= x^3+3x^2-4x-7 between x values 1 and 3


What is the gradient of the quadratic function y=3x²?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning