Question
Find points on the curve 
at which the tangents are (i) parallel to the x-axis (ii) parallel to the y-axis.
Solution
The equation of curve is 
...(1)
Differentiating both sides w.r.t. x, we get,
(i) For the points on the curve, where tangent are parallel to x-axis,
Putting x = 0 in (1), we get,
(ii) For the points on the curve, where tangents are parallel to y-axis.
Putting y = 0 in (1), we get,
