differentiation of tan (1 Viewer)

[apak]

differentiate xtanx
the answer books answer is xsec²x + tanx
but my answer is xsec²x.
was it a error in the book?
thanks

 

[tennille]

You use the product rule:

u=x, v=tanx, u'=1, v'=sec²x

d/dx=vu'+uv'
d/dx=tanx*1+x*sec²x
d/dx=tanx+xsec²x