The formula kappaκ(x)equals=startfraction startabsolutevalue f double prime left parenthesis x right parenthesis endabsolutevalue over left bracket 1 plus left parenthesis f prime left parenthesis x right parenthesis right parenthesis squared right bracket superscript 3 divided by 2 endfraction f′′(x) 1+f′(x)23/2 expresses the curvature of a twice-differentiable plane curve as a function of x. find the curvature function of the curve