Answer:
Step-by-step explanation:
Use the half angle identity for cosine:
cos(x/2)=+ or - sqrt(1+cos(x))/sqrt(2)
I'm going to figure out the sign part first for cos(x/2)...
so x is in third quadrant which puts x between 180 and 270
if we half x, x/2 this puts us between 90 and 135 (that's the second quadrant)
cosine is negative in the second quadrant
so we know that
cos(x/2)=-sqrt(1+cos(x))/sqrt(2)
Now we need cos(x)... since we are in the third quadrant cos(x) is negative...
If you draw a reference triangle sin(x)=3/5 you should see that cos(x)=4/5 ... but again cos(x)=-4/5 since we are in the third quadrant.
So let's plug it in:
cos(x/2)=-sqrt(1+4/5)/sqrt(2)
No one likes compound fractions (mini-fractions inside bigger fractions)
Multiply top and bottom inside the square roots by 5.
cos(x/2)=-sqrt(5+4)/sqrt(10)
cos(x/2)=-sqrt(9)/sqrt(10)
cos(x/2)=-3/sqrt(10)
Rationalize the denominator
cos(x/2)=-3sqrt(10)/10
Step-by-step explanation:
according to the graph, the correct answer is:
possitive : (-1, 2) and (6, oo)
negative : (-oo, -1) and (2, 6)
There are 6 girls who wear glasses in the class, so the remaining must be the boys. 14-6=8 so there must be 8 boys who were glasses
Option C:
Area of the wall 
square feet
Solution:
Length of the wall = 
feet
Width of the wall = 
feet
Area of the wall = length × width
Convert mixed fraction into improper fraction.
Convert improper fraction into mixed fraction.
Area of the wall square feet
Option C is the correct answer.
Answer:
its x^4
Step-by-step explanation:
its x^4
