InterviewSolution
Saved Bookmarks
| 1. |
Consider the differential equation `ydx-(x+y^(2))dy=0`. If for `y=1, x` takes value 1, then value of x when y = 4, isA. 64B. 9C. 16D. 36 |
|
Answer» Correct Answer - C We have, `ydx-(x+y)^(2)dy=0` `rArr" (dx)/(dy)+(-(1)/(y))x=y" ...(i)"` This is a linear differential equation with `"I.F."=e^(int(1)/(y)dy)=(1)/(y)` Multiplying both sides of (i) by `"I.F."=(1)/(y)` and integrating with respect to y, we get `(x)/(y)=int yxx(1)/(y)dy+C` `rArr" "(x)/(y)=y+C" ...(ii)"` It is given that y=1 when x = 1. Putting x = 1, y = 1 in (ii), we get C = 0. Putting C = 0 in (ii), we get `x=y^(2)`. When y = 4 this equation gives x = 16. |
|