Question

The angle between the tangents drawn from the point (1, 4) to the parabola y² = 4x is –

• A. p/6
• B. p/4
• C. p/3
• D. p/2

Answer 1

Answer: (C)

p/3

Answer 2

y = mx + 1/m

tangent passes through (1, 4)

4 = m + 1/m ̃ m² – 4m + 1 = 0

Now angle between the lines is given by

tan q = $\left| \frac{m_{1}–m_{2}}{1 + m_{1}m_{2}} \right|$ ̃ tan q = $\sqrt{3}$̃ q = p/3