I will explain you and pair two of the equations as an example to you. Then, you must pair the others.
1) Two circles are concentric if they have the same center and different radii.
2) The equation of a circle with center xc, yc, and radius r is:
(x - xc)^2 + (y - yc)^2 = r^2.
So, if you have that equation you can inmediately tell the coordinates of the center and the radius of the circle.
3) You can transform the equations given in your picture to the form (x -xc)^2 + (y -yc)^2 = r2 by completing squares.
Example:
Equation: 3x^2 + 3y^2 + 12x - 6y - 21 = 0
rearrange: 3x^2 + 12x + 3y^2 - 6y = 21
extract common factor 3: 3 (x^2 + 4x) + 3(y^2 -2y) = 3*7
=> (x^2 + 4x) + (y^2 - 2y) = 7
complete squares: (x + 2)^2 - 4 + (y - 1)^2 - 1 = 7
=> (x + 2)^2 + (y - 1)^2 = 12 => center = (-2,1), r = √12.
equation: 4x^2 + 4y^2 + 16x - 8y - 308 = 0
rearrange: 4x^2 + 16x + 4y^2 - 8y = 308
common factor 4: 4 (x^2 + 4x) + 4(y^2 -8y) = 4*77
=> (x^2 + 4x) + (y^2 - 2y) = 77
complete squares: (x + 2)^2 - 4 + (y - 1)^2 - 1 = 77
=> (x + 2)^2 + (y - 1)^2 = 82 => center = (-2,1), r = √82
Therefore, you conclude that these two circumferences have the same center and differet r, so they are concentric.
120 square centimeters i think?
Answer:sushi love sushi sushi is life and life is sushi
Step-by-step explanation:
These words related to geometry that are quite hard to define precisely are called the point, the line and the plane. They are called as such, not because you can't necessarily define them.
Answer:
odd
Step-by-step explanation:
Just so you know there are shortcuts for determining if a polynomial function is even or odd. You just to make sure you use that x=x^1 and if you have a constant, write it as constant*x^0 (since x^0=1)
THEN!
If all of your exponents are odd then the function is odd
If all of your exponents are even then the function is even
Now you have -4x^3+4x^1
3 and 1 are odd it is an odd function
This a short cut not the legit algebra way
let me show you that now:
For it to be even you have f(-x)=f(x)
For it be odd you have f(-x)=-f(x)
If you don't have either of those cases you say it is neither
So let's check
plug in -x -4(-x)^3+4(-x)=-4*-x^3+-4x=-4x^3+-4x
that's not the same so not even
with if we factor out -1 .... well if we do that we get -(4x^3+4x)=-f(x)
so it is odd.
