Answer:
B 9, -9
Step-by-step explanation:
x^2 - 81 = 0
Add 81 to each side
x^2 = 81
Take the square root of each side
sqrt(x^2) = sqrt(81)
x = ±9
Answer:
1/4 = 0.25
Step-by-step explanation:
We can start by figuring out the axis of symmetry.
y = x² + 12x = x (x + 12)
So roots are x = -12 or 0
Therefore axis of symmetry is x = (-12 + 0) / 2 = -6
We got x-coordinate of vertex. Now plug in x=-6 to solve for y.
y = (-6)² + 12(-6) = 36 - 72 = -36
Therefore vertex is (-6, -36).
Answer:
(x -6)^2 +(y -3)^2 = 2
Step-by-step explanation:
The midpoint (C) is the center of the circle:
C = ((5, 4) +(7, 2))/2 = ((5+7)/2, (4+2)/2) = (6, 3)
A circle with center (h, k) that goes through point (a, b) can be written as ...
(x -h)^2 +(y -k) ^2 = (a -h)^2 +(b -k)^2
Using the values for this problem, we get ...
(x -6)^2 +(y -3)^2 = (5 -6)^2 +(4 -3)^2
(x -6)^2 +(y -3)^2 = 2