Verified Solution • 2025–26 Session moderate

QJEEM18Ma80ea: JEE Main 2018 Mathematics - Class 12 JEEM18Ma80ea Solution: equals.

lim⁡x→0  (27+x)13−39−(27+x)23\mathop {\lim }\limits_{x \to 0} \,\,{{{{\left( {27 + x} \right)}^{{1 \over 3}}} - 3} \over {9 - {{\left( {27 + x} \right)}^{{2 \over 3}}}}} equals.

Multiple Choice Options

  • A 13{1 \over 3}
  • B −- 13{1 \over 3}
  • C −- 16{1 \over 6}
  • D 16{1 \over 6}

Step-by-Step Verified Solution

Given,

limx→0 (27+x)13−39−(27+x)23\mathop {lim}\limits_{x \to 0} \,{{{{\left( {27 + x} \right)}^{{1 \over 3}}} - 3} \over {9 - {{\left( {27 + x} \right)}^{{2 \over 3}}}}}

=   lim⁡x→0 3[(1+x27)13−1]9[1−(1+x27)23]\mathop {\lim }\limits_{x \to 0} \,{{3\left[ {{{\left( {1 + {x \over {27}}} \right)}^{{1 \over 3}}} - 1} \right]} \over {9\left[ {1 - {{\left( {1 + {x \over {27}}} \right)}^{{2 \over 3}}}} \right]}}

=   lim⁡x→0  (1+x3×27)−13[1−(1+2x3×27)]\mathop {\lim }\limits_{x \to 0} \,\,{{\left( {1 + {x \over {3 \times 27}}} \right) - 1} \over {3\left[ {1 - \left( {1 + {{2x} \over {3 \times 27}}} \right)} \right]}}

=    lim⁡x→0  x813(−2x81)=−16\mathop {\lim }\limits_{x \to 0} \,\,{{{x \over {81}}} \over {3\left( { - {{2x} \over {81}}} \right)}} = - {1 \over 6}

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