AP EAMCET2007MathematicsDifferential Equations
The differential equation obtained by eliminating the arbitrary constants a and b from x y=a e^x+b e^ -x is
Options
- Ax d^2 y d x^2 +2 d y d x -x y=0
- Bd^2 y d x^2 +2 y d y d x -x y=0
- Cx d^2 y d x^2 +2 d y d x +x y=0
- Dd^2 y d x^2 + d y d x -x y=0
Correct answer
A. x d^2 y d x^2 +2 d y d x -x y=0
Step-by-step solution
Given, x y=a e^x+b e^ -x On differentiating w.r.t. x , two times aligned & x d y d x +y=a e^x-b e^ -x & x d^2 y d x^2 + d y d x + d y d x =a e^x+b e^ -x & x d^2 y d x^2 +2 d y d x =x y & x d^2 y d x^2 +2 d y d x -x y=0 aligned