Find the area enclosed by the curves 3x2 + 5y = 32 and y = |x - 2| is: |
$\frac{11}{2}$ $\frac{15}{2}$ $\frac{31}{2}$ $\frac{33}{2}$ |
$\frac{33}{2}$ |
The given curves are parabola $x^2=-\frac{5}{3}(y-\frac{32}{5})$ ... (i) y = x - 2 for x > 2 ... (ii) y = - (x - 2) for x < 2 ... (iii) (i) and (ii) meet at P(3, 1) whereas (i) and (iii) meet at Q (-2, 4) and (ii), (iii) meet at R at (2, 0) as shown in the figure. The vertex of the parabola is at $(0,\frac{32}{5})$ and is downwards. Required area = shaded area in the figure $=\int\limits_{-2}^3y\,dx-ΔQNR-ΔPMR=\int\limits_{-2}^3\frac{1}{2}(32-3x^2)dx-\frac{1}{2}(4.4)-\frac{1}{2}(1.1)=\frac{1}{5}[32x-x^3]_{-2}^3-8-\frac{1}{2}$ $=\frac{1}{5}(32×2-35)-\frac{17}{2}=25-\frac{17}{2}=\frac{33}{2}$ sq. units |