Question

Given this equation of a parabola, does the parabola open upward or downward, and what is its vertex (turning point)? (Hint: First rewrite the equation in standard quadratic form.)
y + x2 + 16x = 4

Answer 1

standart for means put y onn the left and all the rest on the right:
y =- x2 - 16x +4
To find the vertex use formula -b/2a to find x-coordinate.
-(-16)/2*(-1) = -8
To find y-coordinate substitute in the equation:
-64+128 +4 = 68
so vertex is at(-8,68)
To see if it opens down or up just look at the sign in front of x2. Since it's negative, opens down

Answer 2

Thank you so much, I understand it a lot better now :)