The angle of intersection between curve $x y = 6$ and $x^{2} y = 12 ?$

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away

An Intiative by Sri Chaitanya

$\tan^{- 1} (\frac{3}{4})$

$\tan^{- 1} (\frac{3}{11})$

$\tan^{- 1} (\frac{11}{3})$

$0^{\circ}$

answer is B.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

The equation of two curves are $x y = 6$ and $x^{2} y = 12$

from (i) we obtain $y = \frac{6}{x}$ putting this value of $y$ in equation (ii) to obtain $x^{2} (\frac{6}{x}) = 12 \Rightarrow 6 x = 12 \Rightarrow x = 2$

Putting $x = 2$ in (i) or (ii) we get, $y = 3$ . Thus, the two curves intersect at $P (2, 3)$

Differentiating (i) w.r.t. x, we get $x \frac{d y}{d x} + y = 0$

$\Rightarrow \frac{d y}{d x} = \frac{- y}{x} \Rightarrow {(\frac{d y}{d x})}_{(2, 3)} = - \frac{3}{2} = m_{1}$

Differentiating (ii) w.r.t. x, we get $x^{2} \frac{d y}{d x} + 2 x y = 0$

$\begin{array}{l} \Rightarrow \frac{d y}{d x} = \frac{- 2 y}{x} \Rightarrow {(\frac{d y}{d x})}_{(2, 3)} = - 3 = m_{2} \\ \Rightarrow \tan θ = \frac{m_{1} - m_{2}}{1 + m_{1} m_{2}} = (\frac{- 3}{2} + 3) / (1 + (\frac{- 3}{2}) (- 3)) = \frac{3}{11} \\ \Rightarrow θ = \tan^{- 1} \frac{3}{11} . \end{array}$