Question

find the derivative of cosX with first principle of derivative​

Answer 1

Answer:

-sinx.

Step-by-step explanation:

let f(x)=cosx

=cos(x+h)

By First principle of derivative

f '(x)=lim h->0 f(x+h)-f(x)/h

=lim h->0 cos(x+h)- cosx

{cosC-cosD=-2sin(C+D/2)sin(C-D/2)}

I think u can do it here onwards