<h2>
Greetings!</h2>
Answer:
(x + 3)² + ( y - 1)² = 81
Step-by-step explanation:
To go in reverse, you need to remember that in the equation:
(x - a)² + (y - b)² = r²
a is the x coordinate of the centre and b is the y coordinate of the centre.
As -3 is the x coordinate, we can replace a with 3, and then replace b with 1:
(x - -3)² + (y - 1)² = r²
The two negatives change to a positive:
(x + 3)² + ( y - 1)² = r²
If r is already given as 9, r² is simply 9²
(x + 3)² + ( y - 1)² = 9²
(x + 3)² + ( y - 1)² = 81
So the equation of the circle is (x + 3)² + ( y - 1)² = 81
<h2>Hope this helps!</h2>
Answer:
28.26
Step-by-step explanation:
A = pi radius squared
A = 3.14 x 9
A= 28.26
Answer:
(x)^2+ (y+2)^2 = 49
Step-by-step explanation:
The standard form of a circle is
(x-h)^2+ (y-k)^2 = r^2 where (h,k) is the center and r is the radius
(x-0)^2+ (y--2)^2 = 7^2
(x)^2+ (y+2)^2 = 49
2:40 I think, but I may be wrong
Answer:
Step-by-step explanation:
They are testing whether you remember the basic 30,60,90 degree triangle side relationship. The ratio of sides for this triangle are 1 opposite the 30 degree angle, square root of three opposite the 60 degree angle and a hypotenuse of 2 opposite the 90 degree angle.
x/2=2/1
x=4/1=4
bottom answer choice
x/4=3^(1/2)/1
x=4(3^(1/2))
third answer choice