



Use the identity:
and solve for
. You get: 
Do the substitution on the left side to get:

The domain is all the x-values you can use with this function. When dealing with a function like this, you need to ask yourself, what would make the bottom equal to 0? Whatever those numbers are, you do NOT want them in your domain.
A fundamental rule is that you cannot divide by 0 or have 0 as a denominator.
So, you solve x^2+6x=0 to find that x=0 or x=-6 would make the denominator 0.
The domain is everything BUT those two values, because they essentially break your function.
Perceent means parts out of 100
x%=x/100
30/100=30%
9514 1404 393
Answer:
100°
Step-by-step explanation:
Angle AKC is a vertical angle with angle BKD, so has the same measure. Since K is the center of the circle, arc AC has the same measure as angle AKC: 100°.
__
A diagram may help.
Let us assume the width of the rectangle = x cm
Then
The length of the rectangle = (x + 4) cm
It is already given that
Perimeter of the rectangle = 80 cm
Now we also know the formula for perimeter of a rectangle
Perimeter = 2 ( length + width)
80 = 2 (x + 4 + x)
80 = 2 (2x + 4)
80/2 = 2x + 4
40 = 2x + 4
Dividing both sides by 2 we get
20 = x + 2
20 -2 = x
x = 18
Then
Width of the rectangle = 18 cm
Length of the rectangle = (18 + 4) cm
= 22 cm
So the rectangle has a length of 22 cm and a width of 18 cm.