Question

Why is this problem maximum -x^2+2x+4

Answer 1

`\displaystyle\bf\\f(x)=-x^2+2x+4\\\\x_(max)=(-b)/(2a)=(-2)/(2*(-1))=(-2)/(-2)=\boxed{\bf1}\\\\y_(max)=(-\Delta)/(4a)=(-(b^2-4ac))/(4a)=(-(2^2-4*(-1)*4))/(4*(-1))=\\\\\\=(-(4-(-16)))/(-4)=(-(4+16))/(-4)=(-20)/(-4)=(20)/(4)=\boxed{\bf5}\\\\\\\textbf{The maximum has the coordinates: }~~\boxed{\boxed{\bf~M(1,~5)~}}`