NIMCET 2024 — Mathematics PYQ
NIMCET | Mathematics | 2024The value of limx→01−cosxex−e−x−2x is equal to
Choose the correct answer:
- A.
2
- B.
1
- C.
0
(Correct Answer) - D.
-1
0
Explanation
Solution:
Let L=limx→01−cosxex−e−x−2x.
As x→0, the expression takes the form 1−cos0e0−e0−0=1−11−1−0=00.
Applying L'Hôpital's Rule by differentiating the numerator and denominator:
L=x→0limdxd(1−cosx)dxd(ex−e−x−2x)
L=x→0limsinxex−(−e−x)−2
L=x→0limsinxex+e−x−2
As x→0, the expression again takes the form 01+1−2=00.
Applying L'Hôpital's Rule a second time:
L=x→0limdxd(sinx)dxd(ex+e−x−2)
L=x→0limcosxex−e−x
Substitute x=0:
L=cos0e0−e0
L=11−1
L=10=0
Explanation
Solution:
Let L=limx→01−cosxex−e−x−2x.
As x→0, the expression takes the form 1−cos0e0−e0−0=1−11−1−0=00.
Applying L'Hôpital's Rule by differentiating the numerator and denominator:
L=x→0limdxd(1−cosx)dxd(ex−e−x−2x)
L=x→0limsinxex−(−e−x)−2
L=x→0limsinxex+e−x−2
As x→0, the expression again takes the form 01+1−2=00.
Applying L'Hôpital's Rule a second time:
L=x→0limdxd(sinx)dxd(ex+e−x−2)
L=x→0limcosxex−e−x
Substitute x=0:
L=cos0e0−e0
L=11−1
L=10=0

