In: Math
Use implicit differentiation in each of the following problems to find dy/dx. Then determine the equation of a tangent line at the given point.
(a) y = xe^y , at (1/e, 1)
(b) sin x cos y = sin x + cos y, at (0, π/2).
Hint: One of the lines is vertical, so its derivative is undefined at the given point. Recall that the equation of a vertical line has the form x = a.