Q.

Let 0x1-(y'(t))2dt=0xy(t)dt, 0x3, y0y(0) = 0. Then at x = 2, y" + y + 1 is equal to              [2024]

1 2  
2 12  
3 2  
4 1  

Ans.

(4)

We have 0x1 - (y'(t))2 dt = 0xy(t) dt

On differentiating both sides, we get

1 - (y'(x))2 = y(x)

  1 - (y')2 = y2    y2 + (y')2 = 1

 2yy' + 2y" = 0    yy' + y" = 0

So, at x = 2, y" + y + 1 = 0 + 1 = 1.