99. Determine whether the vector field F(x, y) = 1+x2 + e sin(y))i+ (tan 1 (x) + e* cos(y))j is conservative or not. If it is, find a potential function and use it to evaluate the line integral $1 F. dr, where C is the curve defined by r(t) (t + 2t, cos(t)), 1 t 3.