SOLUTION: I am studying for my finals and I need help with Consider y= -2x^2-8x+5 Express it in Vertex form, then find the vertex. I figured part a. out, y=a(x-8)^2+5, xv= 8, yv= 5

Algebra ->  Equations -> SOLUTION: I am studying for my finals and I need help with Consider y= -2x^2-8x+5 Express it in Vertex form, then find the vertex. I figured part a. out, y=a(x-8)^2+5, xv= 8, yv= 5       Log On


   



Question 875255: I am studying for my finals and I need help with
Consider y= -2x^2-8x+5
Express it in Vertex form, then find the vertex.
I figured part a. out, y=a(x-8)^2+5, xv= 8, yv= 5
I still need help with b.
Is the vertex a maximum or minimum point? What is its value

Found 2 solutions by ewatrrr, josgarithmetic:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
y = ax^2 + bx + c
y= -2x^2-8x+5 = -2(x+ highlight_green%282%29)^2 + highlight_red%288%29 + 5
y = -2(x+2)^2 +13, V(-2,13) Opening Downward a<0, V(-2,13) max point
+highlight_green%282%29=+b%2F2a+=+%28-8%29%2F2%28-2%29+
+highlight_red%288%29 = -a(2)^2 = -(-2)(4) = 8

Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
The leading term in general form or the value of the coefficient on the squared binomial will tell you if the graph or equation has vertex as a minimum or as a maximum. y=ax^2+bx+c opens upward for a>0 and opens downward for a<0.

You should study more about how to complete the square to put a quadratic equation into standard form. The term to complete the square for your equation is 4; but you first need to factor the 2 from the two terms containing x.
You should find y=-2%28x-2%29%5E2%2B13.

Read and study this: Completing the Square to Solve General Quadratic Equation - includes showing how to convert to standard form.