The area (in sq. units) of the region enclosed by the parabola \(y = x^{2}\) and the line y = x + 6 is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \(\displaystyle\frac{125}{6}\)
The points of intersection come from
\(x^{2} = x+6\)
\(x^{2}-x-6 = 0\)
\((x-3)(x+2) = 0\)
So x = −2 and x = 3. Between them the line is above the parabola (at x = 0 the line gives 6 and the parabola 0), so the area is the integral of (line − parabola):
\( \displaystyle A = \int_{-2}^{3}\left(x+6-x^{2}\right)dx \)
\( \displaystyle = \left[\frac{x^{2}}{2}+6x-\frac{x^{3}}{3}\right]_{-2}^{3} \)
\( \displaystyle = \left(\frac{9}{2}+18-9\right)-\left(2-12+\frac{8}{3}\right) \)
\( \displaystyle = \frac{27}{2}+\frac{22}{3} = \frac{125}{6} \)