Q. Find the coordinates of the vertex of the following parabola algebraically. Write your answer as an (x,y) point.y=−x2−16x−57Answer:
Factor out x terms: The vertex form of a parabola's equation is y=a(x−h)2+k, where (h,k) is the vertex of the parabola. To find the vertex of the parabola given by y=−x2−16x−57, we need to complete the square to rewrite the equation in vertex form.
Complete the square: First, we factor out the coefficient of the x2 term from the x terms. Since the coefficient is −1, we have:y=−1(x2+16x)−57
Rewrite the equation: Next, we find the value that completes the square for the expression x2+16x. This value is (16/2)2=64. We add and subtract this value inside the parentheses to complete the square:y=−1(x2+16x+64−64)−57
Distribute and simplify: Now we rewrite the equation, grouping the terms that create a perfect square trinomial and combining the constants: y=−1((x+8)2−64)−57
Final vertex form: Distribute the −1 and simplify the constants:y=−(x+8)2+64−57y=−(x+8)2+7
Final vertex form: Distribute the −1 and simplify the constants:y=−(x+8)2+64−57y=−(x+8)2+7Now the equation is in vertex form, y=a(x−h)2+k, where a=−1, h=−8, and k=7. Therefore, the vertex of the parabola is (h,k)=(−8,7).
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