The x -coordinate of the vertex is the equation of the axis of symmetry of the parabola. For a quadratic function in standard form, y=ax2+bx+c , the axis of symmetry is a vertical line x=−b2a .
Answer:

Step-by-step explanation:
Use the distance formula!

If we plug in the coordinates:

That's our answer!
Answer:
.
Step-by-step explanation:
The equation of a circle of radius
centered at
is:
.
.
Differentiate implicitly with respect to
to find the slope of tangents to this circle.
![\displaystyle \frac{d}{dx}[x^{2} + y^{2}] = \frac{d}{dx}[25]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cfrac%7Bd%7D%7Bdx%7D%5Bx%5E%7B2%7D%20%2B%20y%5E%7B2%7D%5D%20%3D%20%5Cfrac%7Bd%7D%7Bdx%7D%5B25%5D)
.
Apply the power rule and the chain rule. Treat
as a function of
,
.
.
.
That is:
.
Solve this equation for
:
.
The slope of the tangent to this circle at point
will thus equal
.
Apply the slope-point of a line in a cartesian plane:
, where
is the gradient of this line, and
are the coordinates of a point on that line.
For the tangent line in this question:
,
.
The equation of this tangent line will thus be:
.
That simplifies to
.
Answer:
Step-by-step explanation:
It is a function. Every x has only 1 y associated with it. You cannot find an exception to this rule.
Stated another more common way: if you take a ruler and lay it flat on the graph so that the ruler is parallel to the y axis, you will find the ruler will go through only one y for every x. That's called the vertical line test.
Answer:
A
Step-by-step explanation: