Find $\displaystyle {f{{\left({x}\right)}}}$ if $\displaystyle {y}={f{{\left({x}\right)}}}$ satisfies

$\displaystyle \frac{{{\left.{d}{y}\right.}}}{{{\left.{d}{x}\right.}}}={28}{y}{x}^{{{3}}}$

and the $\displaystyle {y}$-intercept of the curve $\displaystyle {y}={f{{\left({x}\right)}}}$ is $\displaystyle {6}$.

$\displaystyle {f{{\left({x}\right)}}}=$ Preview Question 6