Solveeit Logo

Question

Mathematics Question on applications of integrals

Find the area of the smaller region bounded by the ellipse x29\frac{x^2}{9}+y24\frac{y^2}{4}=1 and the line

x3\frac{x}{3}+y2\frac{y}{2}=1

Answer

The area of the smaller region bounded by the ellipse,x2/9+y2/4=1,and the line,

x3\frac{x}{3}+y2\frac{y}{2}=1,is represented by the shaded region BCAB as

∴Area BCAB=Area(OBCAO)–Area(OBAO)

=

\int_{0}^{3} 2\sqrt{1-\frac{x^2}{9}} \,dx$$$$-\int_{0}^{3} 2(1- \frac {x}{3}) \,dx

=23\frac 23[

03912dx\int_{0}^{3} \sqrt{9-1^2} \,dx

]-

03(3x)dx\int_{0}^{3} (3-x) \,dx

=23\frac 23[\frac{x}{2}$$\sqrt{9-x^2}+92\frac{9}{2}sin-1x3\frac{x}{3}]30-23\frac 23[3x-x22\frac{x^2}{2}]30

=23\frac 23[92\frac{9}{2}(π2\frac{π}{2})]-23\frac 23[9-92\frac{9}{2}]

=23\frac 23[9π4\frac{9π}{4}-92\frac{9}{2}]

=23\frac 23×94\frac{9}{4}(π-2)

=32\frac 32(π-2)units