Question

the equation of the tangent to the curve y=xsinx at the point (pi/2, pi/2) is

Answer 1

take the derivative
= sin(x) + x*cos(x)

Answer 2

now you have the function that gives you slope
plug in pi/2
sin(pi/2) + (pi/2)(cos(pi/2)
=1
y = mx+b but m = 1
y = x+b
pi/2=pi/2+b b = 0
so y = x is the equation tangent to the curve at that point