Determine the equation of the tangent line to the function f(x) = x + Sinx at x = pie

Answer 1

first find the slope at x = pi

dy/dx = 1 + cos x = 1+cos pi = 1-1 = 0
so the line is horizontal

at x = pi
y = pi + sin pi = pi + 0 = pi
so the equation of our line is
y = pi

Answer 2

Thank you Damon!