Question

The co-ordinates of the point on the $\sqrt{x}+\sqrt{y}=6$ at which the tangent is equally inclined the axes is

• A. $(4,4)$
• B. $(9,9)$
• C. $(1,1)$
• D. $(6,6)$

Answer 1

Answer: (B)

$\frac{dy}{dx}=-\sqrt{\frac{y}{x}}=-1$
$y=x$
$\sqrt{x}+\sqrt{x}=6$
$x=9,y=9$