Q.

The area of the region enclosed by the parabolas y=4x-x2 and 3y=(x-4)2 is equal to                            [2024]

1 6  
2 4  
3 143  
4 329  

Ans.

(1)

Given, y=4x-x2                              ...(i)

3y=(x-4)2                                      ...(ii)

From (i),

3y=3(4x-x2)=12x-3x2

From (ii),

(x-4)2=12x-3x2

x2-8x+16=12x-3x2x2-5x+4=0

(x-1)(x-4)=0x=1,4

Points of intersection are (1,3) and (4,0)

Required area = 14[(4x-x2)-(x-4)23]dx

=[2x2-x33-13(x-4)33]14

=[(32-643-13(0))-(2-13-13(-273))]

=30-643+13-3=27-21=6 sq. units