Manipal MET2015MathematicsApplication of Derivatives
The greatest value of the function f(x)=x e^ -x in [0, ) , is
Options
- A0
- B1 e
- C-e
Correct answer
B. 1 e
Step-by-step solution
We have, f(x)=x e^ -x On differentiating both sides w.r.t. x , we get f^ (x)=e^ -x (1-x) Put f^ (x)=0 x=1 Now, f(0)=0 and _ x f(x)= _ x x e^ -x = _ x x e^x = _ x 1 ^x =0 Hence, the greatest value of f(x) is 1 e .