JAMIA 2021 — Mathematics PYQ
JAMIA | Mathematics | 2021Maximum value of(x1)x is
Choose the correct answer:
- A.
e
- B.
ee
- C.
e1/e
(Correct Answer) - D.
(1/e)1/e
e1/e
Explanation
1. Let the function be:
y=(x1)x=x−x
2. Take natural log (ln) on both sides:
lny=ln(x−x)
lny=−xlnx
3. Differentiate with respect to x:
y1dxdy=−[x⋅x1+lnx⋅1]
y1dxdy=−(1+lnx)
dxdy=−(x1)x(1+lnx)
4. Set dxdy=0 for maximum value:
−(1+lnx)=0
lnx=−1
x=e−1=e1
5. Substitute x=e1 into the original function:
ymax=(1/e1)1/e
ymax=e1/e
Final Answer:
e1/e
Explanation
1. Let the function be:
y=(x1)x=x−x
2. Take natural log (ln) on both sides:
lny=ln(x−x)
lny=−xlnx
3. Differentiate with respect to x:
y1dxdy=−[x⋅x1+lnx⋅1]
y1dxdy=−(1+lnx)
dxdy=−(x1)x(1+lnx)
4. Set dxdy=0 for maximum value:
−(1+lnx)=0
lnx=−1
x=e−1=e1
5. Substitute x=e1 into the original function:
ymax=(1/e1)1/e
ymax=e1/e
Final Answer:
e1/e

