Answer:
(the relation you wrote is not correct, there may be something missing, so I will simplify the initial expression)
Here we have the equation:
We can rewrite this as:
Now we can add and subtract cos^2(x)*sin^2(x) to get:
We can complete squares to get:
and we know that:
cos^2(x) + sin^2(x) = 1
then:
This is the closest expression to what you wrote.
We also know that:
sin(x)*cos(x) = (1/2)*sin(2*x)
If we replace that, we get:
Then the simplification is:
Electrons do not have FEET
First find the radius of circle A. You know that the equation is r^2*pi, so just divide both by pi.
r^2*pi=16pi
/pi /pi
r^2=16
R is 4. That means that circle B is 2, since its radius is half that of circle A.
C=pi2r
C=pi2(2)
C=pi4
C=4pi
The answer is 4pi.