Answer:
(x + 4)^2 + (y - 8)^2 = 81
or
(x + 4)^2 + (y - 8)^2 = 9^2 depending on how your teacher wants it written.
Step-by-step explanation:
The standard form for a circle is
(x + h)^2 + (y + k)^2 = r^2
r is the radius.
You are given the diameter
r = d/2
r = 18/2
r = 9
So you already have the right hand side of the equation
(x + h)^2 + (y + k)^2 = 9*2
(x + h)^2 + (y + k)^2 = 81
You basically have h and k as well. They come from the center point.
h = 4
k = - 8
So the equation of the circle (and the answer) is
(x + 4)^2 + (y - 8)^2 = 81
One question remains. Why do the x and y values change signs? If you know what the distance formula is, then what you are finding is the distance r of all points on the circle from the center of the circle.
It is the distance formula that is actually the formula for the circle.
If one third of t is 7 than t is equal to 21
Answer:
C, D, E, F
Step-by-step explanation:
Remember y=mxb?
m is slope and b is y-intercept
so y=2/7x-9
Remember that slope is RISE/RUN so for every 2 squares that you go up, you go 7 squares to the right.
Also remember that since your graph is going thru your Cartiesian Plane in quadrent 4, your y value in your ordered pairs will most probably be a negative.
Please see the image to help you viualize this.
Answer:
Step-by-step explanation:
Combine real terms and combine complex terms
1) 3 + 2i + 2 - 5i = 3 +2 + 2i - 5i
= 5 + (2-5)i
= 5 + (-3)i
= 5 - 3i
3) 2 - (1 - 2i) + (4 -5i ) - (1 - 3i) = 2 -1 + 2i + 4 - 5i - 1 + 3i
{- is distributed to (1 - 2i) & - is distributed to (1- 3i)}
= 2 - 1 + 4 + 1 + 2i - 5i + 3i
= 6 +0i = 6
5) 4 - 3i + 4 + 3i = 4 +4 -3i + 3i
= 8
7) (3 - 2i)² + (3 +2i) = 3² - 2*3*2i + (2i)² + 3 + 2i {(a - b)² = a² - 2ab +b²}
= 9 -12i + 4i² + 3 + 2i
= 9 - 12i + 4*(-1) + 3 + 2i {i² = -1}
= 9 +3 - 4 - 12i +2i
= 8 - 10i