Question

find the derivatives of sinxcosx by 1st principle​

Answer 1

Step-by-step explanation:

by the first principle

d/dx(v.u)=vd/dx u+ud/dx v

so that ,d/dx( sinx.cosx)

sinx d/dx cosx+cosx d/dxsinx

sinx(-sinx)+cosx.cosx

cos^2x-sin^2x

cos2x