A parabola whose equation is y=x2-2x+k has a turning point with coordinates (1,-5). Find the value of K
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Originally Posted by hawk123 A parabola whose equation is y=x2-2x+k has a turning point with coordinates (1,-5). Find the value of K $\displaystyle y(1) = -5$ $\displaystyle -5 = (1)^2 - 2(1) + k$
y = x^2 - 2x + k = x^2 - 2x + (-2/2)^2 - (-2/2)^2 + k = x^2 - 2x + 1 - 1 + k = (x^2 - 2x + 1) + (k - 1) = (x - 1)^2 + (k - 1) = (x - H)^2 + (K) where (H,K) is the turning point = (1, -5) hence -5 = k - 1 k = -4
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