Q.

Let f(α) denote the area of the region in the first quadrant bounded by x=0, x=1, y2=x and y=|αx-5|-|1-αx|+αx2. 

Then (f(0)+f(1)) is equal to     [2026]

1 9  
2 12  
3 7  
4 14  

Ans.

(3)

at α=0f(0)

x=0, x=1, y2=x

y=|0·x-5|-|1-0·x|+0·x2

y=4

A1=01(4-x)dx

=4x-x3/23/2|01

=4-23(1)=103

at α=1f(1)

x=0, x=1, y2=x

y=|x-5|-|1-x|+x2, x(0,1)

y=5-x-(1-x)+x2

y=4+x2

[IMAGE 245]--------

A2=01[(4+x2)-x]dx

=4x+x33-x3232|01

=4+13-23=113

|f(0)+f(1)|=|A1+A2|=|103+113|=|213|=7

option (3)