Verified Solution • 2025–26 Session moderate

QJEEM20Ma6abf: JEE Main 2020 Mathematics - Class 12 JEEM20Ma6abf Solution: The integral is equal to : (where C is a constant of integration)

The integral ∫dx(x+4)87(x−3)67\int {{{dx} \over {{{(x + 4)}^{{8 \over 7}}}{{(x - 3)}^{{6 \over 7}}}}}} is equal to :
(where C is a constant of integration)

Multiple Choice Options

  • A 12(x−3x+4)37+C{1 \over 2}{\left( {{{x - 3} \over {x + 4}}} \right)^{{3 \over 7}}} + C
  • B (x−3x+4)17+C{\left( {{{x - 3} \over {x + 4}}} \right)^{{1 \over 7}}} + C
  • C −113(x−3x+4)137+C- {1 \over {13}}{\left( {{{x - 3} \over {x + 4}}} \right)^{{{13} \over 7}}} + C
  • D - (x−3x+4)−17+C{\left( {{{x - 3} \over {x + 4}}} \right)^{-{1 \over 7}}} + C

Step-by-Step Verified Solution

∫dx(x+4)87(x−3)67\int {{{dx} \over {{{(x + 4)}^{{8 \over 7}}}{{(x - 3)}^{{6 \over 7}}}}}}

= ∫dx(x+4)2(x−3x+4)67\int {{{dx} \over {{{\left( {x + 4} \right)}^2}{{\left( {{{x - 3} \over {x + 4}}} \right)}^{{6 \over 7}}}}}}

Put x−3x+4{{{x - 3} \over {x + 4}}} = t

⇒\Rightarrow {(x+4)−(x−3)(x+4)2}dx\left\{ {{{\left( {x + 4} \right) - \left( {x - 3} \right)} \over {{{\left( {x + 4} \right)}^2}}}} \right\}dx = dt

⇒\Rightarrow dx(x+4)2=dt7{{dx} \over {{{\left( {x + 4} \right)}^2}}} = {{dt} \over 7}

= 17∫dt(t)67{1 \over 7}\int {{{dt} \over {{{\left( t \right)}^{{6 \over 7}}}}}}

= 17(t1717){1 \over 7}\left( {{{{t^{{1 \over 7}}}} \over {{1 \over 7}}}} \right) + C

= (x−3x+4)17{\left( {{{x - 3} \over {x + 4}}} \right)^{{1 \over 7}}} + C

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