AP EAMCET2002MathematicsApplication of Derivatives
The functions f(x)=x e^ -x , (x R) attains a maximum value at x is equal to
Options
- A1
- B2
- C1 e
- D3
Correct answer
A. 1
Step-by-step solution
We have, f(x)=x e^ -x f^ (x)=-x e^ -x +e^ -x For maximum or minimum, put f^ (x)=0 aligned & -x e^ -x +e^ -x =0 x=1 & f^ (x)=x e^ -x -e^ -x -e^ -x =(x-2) e^ -x & f^ (1)=(1-2) e⁻¹=- ve aligned f(x) is maximum at x=1 .