MHT CET202521 Apr 2025Morning ShiftMathematicsDifferentiationActual
If ( a + b x) e ^ y x =x , then x^3 ~d ^2 y d x^2 is equal to
Options
- A( y dy d x -x )^2
- B(x dy d x - y )^2
- C(x dy d x + y )^2
- D( y dy d x +x )^2
Correct answer
B. (x dy d x - y )^2
Step-by-step solution
Given the equation (a+bx)e^ y x = x , taking the natural logarithm yields y x = x - (a+bx) . Solving for y gives y = x x - x (a+bx) . Differentiating both sides, dy dx = x + 1 - (a+bx) - bx a+bx . Rewriting using the earlier logarithmic relationship, dy dx = y x + 1 - bx a+bx . Simplifying the constant terms produces dy dx = y x + a a+bx . Multiplying through by x gives x dy dx - y = ax a+bx . Differentiating again, d^2y dx^2 = x dy dx -y x^2 - ab (a+bx)^2 . Substituting the previous result yields d^2y dx^2 = a x(a