find dy/dx for y=arctan(x/2)

Question

i'm getting 4/(x^2+4)

my friend is getting 2/(4+x^2)

could someone point me in the right direction?

tahnk you

Answer 1

Your friend may be right.

Check this:

dy/dx = (1/2)/[1 +(x/2)^2] = 2/(4 + x^2)

Answer 2

Drat.

thank you