You can put this solution on YOUR website! The function y = x + tan(x) does not go through the point (pi,2pi). I assume the given point is supposed to be (pi,pi).
The slope of the tangent line is given by the derivative of the function:
dy/dx = m = 2 + (tan(x))^2
At x = pi, we have m = 2 + (tan(pi))^2 = 2
Use the point-slope form:
y - pi = 2(x-pi) -> y = 2x - pi