Q. Find the coordinates of the vertex of the following parabola algebraically. Write your answer as an (x,y) point.y=−2x2+8xAnswer:
Factor out x terms: The vertex form of a parabola 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=−2x2+8x, we need to complete the square to convert the equation into vertex form.
Complete the square: First, factor out the coefficient of x2 from the x terms: y=−2(x2−4x). Leave a space to add and subtract the necessary term to complete the square.
Simplify the equation: To complete the square, take half of the coefficient of x, which is 4, square it, and add and subtract it inside the parentheses: y=−2(x2−4x+(4/2)2−(4/2)2).
Factor the trinomial: Simplify the equation by adding the square and its negative inside the parentheses: y=−2(x2−4x+4−4).
Distribute −2: Now, factor the perfect square trinomial inside the parentheses and simplify the constant term: y=−2((x−2)2−4).
Final vertex form: Distribute the −2 to the terms inside the parentheses: y=−2(x−2)2+8.
Final vertex form: Distribute the −2 to the terms inside the parentheses: y=−2(x−2)2+8.Now we have the equation in vertex form: y=−2(x−2)2+8. The vertex (h,k) can be read directly from the equation as (2,8).
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