Question

The answer is 3
I need explanation​

Answer 1

$HEYA \: \\ \\ lim \: \: \: \: \: \: \: \sqrt[n]{(a - x)} \: - \: \: \sqrt[n]{a} \\ x - > 0 \: \: \: \: - - - - - - - \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: x \\ \\ put \: x \: = 0 \: \: we \: get \: 0 \div 0 \: form . \: to \: come \: \\ from \: this \: form \: we \: use \: l \: hospitals \: rule \\ which \: States \: that \: Differentiate \: Numerator \: \\ and \: denominator \: seperetly \: till \: we \: come \: out \: from \: \\ 0 \div 0 \: form \\ \\ lim \: \: \: \: \: \: \: \: \: (1 \div n) \times (a - x) {}^{(1 \div n) - 1} \times ( - 1) \\ x - > 0 \\ \\ now \: put \: x \: = 0 \\ \\ ( - 1 \div n) \times (a {}^{(1 \div n) - 1} )$