In order to find the extrema, we need to solve the equation
dxdf(x)=0(the derivative equals zero),
and the roots of this equation are the extrema of this function:
dxdf(x)=the first derivativex(tan2(x)+1)atan(−2+x1)−x2((−2+x1)2+1)tan(x)−x2tan(x)atan(−2+x1)=0Solve this equationSolutions are not found,
function may have no extrema