The standard form of a circle is:

Your center is
and your radius is 
Plug them into the equation and you get


The correct answer is D.
Answer:
see explanation
Step-by-step explanation:
The y- intercept is at (0, 6) ⇒ c = 6
The x- coordinate of the vertex is at the midpoint of the zeros, that is
m =
=
= - 2
Since the zeros are x = - 3 and x = - 1 then the factors are (x + 3), (x + 1) and
f(x) = a(x + 3)(x + 1) = a(x² + 4x + 3)
Comparing with f(x) = ax² + 8x + 6 ⇒ a = 2
Thus
f(x) = 2x² + 8x + 6
Substitute m = - 2 into the equation for value of n
n = 2(- 2)² + 8(- 2) + 6 = 8 - 16 + 6 = - 2
Hence
c = 6, m = - 2, a = 2, n = - 2
<h3>
Answer: -2</h3>
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Work Shown:


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Explanation:
In the second step, I multiplied top and bottom by 1/x. This divides every term by x. Doing this leaves us with various inner fractions that have the variable in the denominator. Those inner fractions approach 0 as x approaches infinity.
I'm using the rule that

where k is some positive real number constant.
Using that rule will simplify the expression greatly to leave us with -2/1 or simply -2 as the answer.
In a sense, the leading terms of the numerator and denominator are -2x and x respectively. They are the largest terms for each, so to speak. As x gets larger, the influence that -2x and x have will greatly diminish the influence of the other terms.
This effectively means,

I recommend making a table of values to see what's going on. Or you can graph the given function to see that it slowly approaches y = -2. Keep in mind that it won't actually reach y = -2 itself.
So if we see the first one (8,4) x=8 and y=4
And we see the 2nd one (4,y) x=4 and y=?
We notice that the value of x its been halved. So y varies with x so y value also has to be halved so y= 2
= cos( -x ) * [ - sin( - x ) ] = cosx * sinx ;
cosx * sin x is the right answer !