The equation of the tangent to the curve , that is parallel to the -axis, is
- (A)
- (B)
- (C)✓ Correct
- (D)
Answer: (C)
Solution
A tangent parallel to the -axis has zero slope, so we set . Differentiating gives , which vanishes when , that is . The height there is , so the horizontal tangent is the line .
JEE Main · 2010 · 11 Apr 2010 · Offline · Single correct option