Assertion (A) : Area of $\mathrm{\Delta le}$ formed by tangent to the curve $\mathrm{xy}={\mathrm{c}}^2$ with co-ordinate axes is 2c² s.u.
Reason (R) : Area of $\mathrm{\Delta le}$ formed by the line $\frac{\mathrm{x}}{\mathrm{a}}+\frac{\mathrm{y}}{\mathrm{b}}=1$ with co-ordinate axes is $\frac{1}{2}\left|\mathrm{ab}\right|$. s.u.
 

 $\mathrm{xy}={\mathrm{c}}^2$
Diff. w.r.t. ‘x’
$\mathrm{x}\frac{\mathrm{dy}}{\mathrm{dx}}+\mathrm{y}=0$
 $\frac{\mathrm{dy}}{\mathrm{dx}}=\frac{-\mathrm{y}}{\mathrm{x}}$

$\mathrm{m}={\left(\frac{\mathrm{dy}}{\mathrm{dx}}\right)}_{\left({\mathrm{x}}_1,{\mathrm{y}}_1\right)}=\frac{-{\mathrm{y}}_1}{{\mathrm{x}}_1}$ 
Equation of tangent at $\left({\mathrm{x}}_1,{\mathrm{y}}_1\right)$ in 
$\begin{array}{l}\mathrm{y}-{\mathrm{y}}_1=\frac{-{\mathrm{y}}_1}{{\mathrm{x}}_1}\left(\mathrm{x}-{\mathrm{x}}_1\right)\\ \frac{\mathrm{y}}{{\mathrm{y}}_1}-\frac{{\mathrm{y}}_1}{{\mathrm{y}}_1}=\frac{\mathrm{x}}{{\mathrm{x}}_1}+\frac{{\mathrm{x}}_1}{{\mathrm{x}}_1}\\ \frac{\mathrm{y}}{{\mathrm{x}}_1}+\frac{\mathrm{y}}{{\mathrm{y}}_1}=2\\ \frac{\mathrm{x}}{{\mathrm{x}}_1}+\frac{\mathrm{y}}{{\mathrm{y}}_1}=2\\ \frac{\mathrm{x}}{2{\mathrm{x}}_1}+\frac{\mathrm{y}}{2{\mathrm{y}}_1}=1\end{array}$
Area of $\mathrm{\Delta le}$ formed by the tangent with axes is $\frac{1}{2}\left|2{\mathrm{x}}_1.2{\mathrm{y}}_1\right|$
$\begin{array}{l}=2{\mathrm{x}}_1{\mathrm{y}}_1\\ =2{\mathrm{c}}^2\end{array}$
$\therefore \left({\mathrm{x}}_1,{\mathrm{y}}_1\right.$lie on the curve xy = c²)
$\therefore$  A is true, R is true
R is correct explanation of A