NIMCET 2010 — Mathematics PYQ
NIMCET | Mathematics | 2010The value of the integral ∫04π3+sin2xsinx+cosxdx is:
Choose the correct answer:
- A.
log2
- B.
log3
- C.
41log3
(Correct Answer) - D.
81log3
41log3
Explanation
Step 1: Use Substitution
We know that the derivative of (sinx−cosx) is (cosx+sinx).
Let t=sinx−cosx
Then, dt=(cosx+sinx)dx
Step 2: Change the Limits
-
When x=0: t=sin0−cos0=0−1=−1
-
When x=4π: t=sin4π−cos4π=21−21=0
Step 3: Express the denominator in terms of t
Squaring t=sinx−cosx:
Substituting this into the denominator:
Step 4: Substitute everything into the integral
Step 5: Integrate using the formula ∫a2−x2dx=2a1loga−xa+x
Here a=2:
Conclusion:
The value of the integral is 41log3.
Correct Option:
(c) 41log3
Explanation
Step 1: Use Substitution
We know that the derivative of (sinx−cosx) is (cosx+sinx).
Let t=sinx−cosx
Then, dt=(cosx+sinx)dx
Step 2: Change the Limits
-
When x=0: t=sin0−cos0=0−1=−1
-
When x=4π: t=sin4π−cos4π=21−21=0
Step 3: Express the denominator in terms of t
Squaring t=sinx−cosx:
Substituting this into the denominator:
Step 4: Substitute everything into the integral
Step 5: Integrate using the formula ∫a2−x2dx=2a1loga−xa+x
Here a=2:
Conclusion:
The value of the integral is 41log3.
Correct Option:
(c) 41log3
