Question:
Find a point on the curve $y=x^{2}$ where the Slope of the tangent is equal to the $x$-coordinate of the point.
Solution:
Given:
The curve is $y=x^{2}$
$y=x^{2}$
Differentiating the above w.r.t $x$
$\Rightarrow \frac{d y}{d x}=2 x^{2-1}$
$\Rightarrow \frac{d y}{d x}=2 x \ldots(1)$
Also given the Slope of the tangent is equal to the $x$-coordinate,
$\frac{\mathrm{dy}}{\mathrm{dx}}=x \ldots(2)$
From (1) \& (2), we get,
i.e, $2 x=x$
$\Rightarrow x=0$
Substituting this in $y=x^{2}$, we get,
$y=0^{2}$
$\Rightarrow y=0$'
Thus, the required point is $(0,0)$