Question 1026259
{{{y = (2x)/(x+2)}}} ==> y'={{{4/(x+2)^2}}}.

This function is not differentiable at -2, which is safely outside [-1,2], but will always have a positive derivative whenever it exists.  The function is increasing over ({{{-infinity}}},-2) and (-2,{{{infinity}}}).  Thus the maximum value of the function over [-1,2] exists at the endpoint x = 2, with function value {{{f(2) = (2*2)/(2+2) = 1}}}.