Question 422863
The turning point (vertex) is the point where the derivative is equal to zero.
Thus dy/dx = 0 = -2x + 4 -> x = 2
The value of the y coordinate at this value of x is y = -(2)^2 + 4*2 + 1 = 5
Ans: turning point = (2,5)
{{{graph(300,300,-8,8,-10,10,-x^2+4x+1)}}}