Posted by Janet on Sunday, March 20, 2011 at 7:47pm.
I need help with finding first and second derivativesimplify your answer.
Y=xtan(x)
I solved first derivative
xsec^2(x) + tan(x)
I don't understand how to get the first...can someone show me the steps with explanation?

Calculus  Janet, Sunday, March 20, 2011 at 7:48pm
Sorry I don't understand how to get the second derivative, I gsolved the first derivative already

Calculus  bobpursley, Sunday, March 20, 2011 at 8:04pm
well, the derivative of tan(x) is sec^2(x) that part is trivial.
derivative of x(sec^2(x)) is
y=uv
y'=vu' + uv'
let u=x v=sec^2=cos^2
u'=1 v'=2cos^3*(sin)
v'=2tan(x)sec^2x
so overall, the
f"=2x tan(x)sec^2(x)+sec^2(x)+sec^2(x)