/? x f(x,y)]=? /? x [3-(x^2+y^2)]=-2x
/? y f(x,y)]=? /? y [3-(x^2+y^2)]=-2y
Area=A=∫∫ (on 0 ≤ x 2+y 2 ≤ 2) {1+[? /? x [? (x,y)]]? + [? /? y [? (x,y)]]? } }^( 1/2) dxdy
= ∫∫ (in 0 ≤ x 2+y 2 ≤ 2) {1+4 (x 2+y 2)} dxdy
In polar coordinates,
X=r*cos(a)
Y=r*sin(a)
A=∫∫ (about 0 ≤ R 2 ≤ 2, 0 ≤ A ≤ 2π) {(1+4 (r 2) [cos (a)] 2+[sin (a)] 2} (/kloc-)
= ∫ ∫ (For 0 ≤ r 2 ≤ 2, 0 ≤ a ≤ 2 π) {(1+4 (r 2)} (1/2) Dr. R.
= 2π ∫ (0 ≤ r 2 ≤ 2) {(1+4 (r 2)} (1/2) r dr
= 2π[(2/3){(r/4){2r√( 1 + 4r? )+ ln|2r + √( 1 + 4r? )|} + (? ){rln|2r+ √( 1 + 4r? )| - √( 1 + 4r? )}}] _ Calculate r from 0 to 2
= 2π[(2/3){( 1/2){ 4 √( 1 7)+ln | 4+√( 17)| }+(? ){ 2ln | 4+√( 17)|-√( 17)} }]+π/2
The shaded part in the above figure consists of eight green figures, the area of which is1/4, the area of a circle with a radius of 16÷2-1/2, and the area of a squar