Question:
The area (in sq. units) in the first quadrant bounded by the parabola, $y=x^{2}+1$, the tangent to it at the point $(2,5)$ and the coordinate axes is :
Correct Option: , 2
Solution:
The equation of parabola $x^{2}=y-1$
The equation of tangent at $(2,5)$ to parabola is
$y-5=\left(\frac{d y}{d x}\right)_{(2,5)}(x-2)$
$y-5=4(x-2)$
$4 x-y=3$
Then, the required area
$=\int_{0}^{2}\left\{\left(x^{2}+1\right)-(4 x-3)\right\} d x$-Area of $\triangle A O D$
$=\int_{0}^{2}\left(x^{2}-4 x+4\right) d x-\frac{1}{2} \times \frac{3}{4} \times 3$
$=\left[\frac{(x-2)^{3}}{3}\right]_{0}^{2}-\frac{9}{8}=\frac{37}{24}$