Q.

The area enclosed by the curves xy+4y=16 and x+y=6 is equal to:               [2024]

1 28-30loge2      
2 32-30loge2      
3 30-28loge2      
4 30-32loge2  

Ans.

(4)

We have, y=16x+4 and x+y=6y=6-x

For intersecting points:

6-x=16x+4(6-x)(x+4)=16

x2-2x-8=0x2-4x+2x-8=0

x(x-4)+2(x-4)=0

(x+2)(x-4)=0x=-2, 4

  y=8,whenx=-2 and y=2,whenx=4

So, Area=-24((6-x)-16x+4)dx=[6x-x22-16loge(x+4)]-24

=24-8-16loge8+12+2+16loge2=30-16loge(82)

=30-16loge22=30-32loge2