If $\int \, $x5.e$-$4x3 dx = ${1 \over {48}}$e$-$4x3 f(x) + C, where C is a constant of inegration, then f(x) is equal to -

Question

If $\int \, $x⁵.e^$-$4x³ dx = ${1 \over {48}}$e^$-$4x³ f(x) + C, where C is a constant of inegration, then f(x) is equal to -

$-$2x³ $-$ 1