3bin8Express the function y= 2x2 + 8x + 1 in vertex form.y=a0(x +NEXT QUESTIONASK FOR HELPTURNI
Accepted Solution
A:
Answer:y = 2[x + 2]^2 - 7Step-by-step explanation:We want to express y= 2x2 + 8x + 1 in vertex form.Rewrite y= 2x2 + 8x + 1 as y= 2(x^2 + 4x) + 1Now "complete the square" of x^2 + 4x:Identify the coefficient of the x term. it is 4. Take half of this: it is 2.Square this result (that is, square 2) and then add the result to x^2 + 4x, and then subtract it: x^2 + 4x becomes x^2 + 4x + 4 - 4. Convince yourself that x^2 + 4x + 4 - 4 is identical to x^2 + 4x. x^2 + 4x + 4 can be rewritten as (x + 2)^2.Going back to our equation y= 2(x^2 + 4x) + 1 (see above),replace "x^2 + 4x" in this equation with "(x + 2)^2 - 4:Then: y= 2(x^2 + 4x) + 1 becomes: y= 2( [x + 2]^2 - 4 ) + 1, or y = 2[x + 2]^2 - 8 + 1, or y = 2[x + 2]^2 - 7Compare this to the standard equation y = a(x-h)^2 + k. We see that h = -2 and k = -7.The given equation, expressed in vertex form, is y = 2[x + 2]^2 - 7. The vertex is at (-2, -7).