VERY URGENT HAVE A TEST TO TAKE

1 answer:

5 0

The easiest way is to try the point (-4,1), that is, x=-4, y=1,
to see which equation works.
b works.

The usual way to do it is to find the equation of the circle
standard form of a circle is (x-h)²+(y-k)²=r², (h,k) are the coordinates of the center, r is the radius.
in this case, the center is (-2,1), so (x+2)²+(y-1)²=r²
the given point (-4,1) is for you to find r: (-4+2)²+(1-1)²=r², r=2
so the equation is (x+2)²+(y-1)²=2²
expand it: x²+4x+4+y²-2y+1=4
x²+y²+4x-2y+1=0, which is answer b.

You might be interested in

Find the domain of the function in interval notation: f(x) =1/ x + 22

cricket20 [7]

That's the answer

x = - 1/22

6 0

3 years ago

How does writing equivalent equations help you solve a system of equations?

Alexus [3.1K]

Writing equivalent equations help you solve system of equations because it sets it up for being broken down part by part.

3 0

3 years ago

What is the coefficient of n^2 in the sum of -5^4+4n^2-n+5 and 7n^4-5n^3-9n^2+3n+2

pickupchik [31]

Hello :
-5^4+4n^2-n+5 : the coefficient of n^2 is : 4<span>
7n^4-5n^3-9n^2+3n+2 : </span><span>he coefficient of n^2 is :-9</span>

4 0

3 years ago

Solve using demoivres theorem

pashok25 [27]

It's difficult to make out, but I think the task is to expand

$(\sqrt3-i)^4$

Write the number in polar form first:

$\sqrt3-i=2e^{-i\pi/6}$

By DeMoivre's theorem, you have

$(\sqrt3-i)^4=\left(2e^{-i\pi/6}\right)^4=2^4e^{-i4\pi/6}=16e^{-i2\pi/3}$

and converting back to Cartesian form, this number is equivalent to

$16\left(\cos\dfrac{2\pi}3-i\sin\dfrac{2\pi}3\right)=16\left(-\dfrac12+-\dfrac{\sqrt3}2\right)=-8(1+i\sqrt3)$

3 0

3 years ago

I need to know if the following questions are true or false

Triss [41]

Answer:

False

Step-by-step explanation:

To find <A, we can do 5x - 80 = 3x + 20.

As we simplify, we will get 2x = 100, which is x = 50

Therefore, <A will be 50 degrees and not 45 degrees.

Also, if you need y, you can do:

3y - 7 = y + 7

2y = 14

y = 7

5 0

3 years ago