Question

Find dy/dx if y=sinx+cosx

Answer 1

d(sinx)/dx = cos x

d( cos x)/dx = - sinx

So d( sinx + cosx)/dx = cosx - sinx

Answer 2

y=sinx+cosx,

then

dy/dx =d(sinx)/dx + d(cosx)/dx,

dy/dx = cosx - sinx