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Question: Answered & Verified by Expert
If dxx31+x623 =xfx1+x613+C, where C is a constant of integration, then the function fx is equal to
MathematicsIndefinite IntegrationJEE MainJEE Main 2019 (08 Apr Shift 2)
Options:
  • A 3x2
  • B -12x3
  • C -16x3
  • D -12x2
Solution:
1196 Upvotes Verified Answer
The correct answer is: -12x3

We have, dxx31+x623=xfx1+x613+C

Now, I=dxx71x6+123

Put, t=1x6+1dt=-6x7dx

I=-16dtt23=-12t13+C, where C is the constant of integration=-121x6+113+C=-121+x613x2+C

fx=-12x3

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