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
Answer:
Step-by-step explanation:
we have
Remember that
and
substitute
The probability of landing on red the first time is 1/2, because there are two colors on the wheel. The probability of landing on blue the second time in that individual round is 1/2. The probability of landing on red the third time in that individual round is 1/2.
Multiply 1/2 by 1/2 by 1/2
Answer: The probability is 1/8
Answer:
A
Step-by-step explanation:
the answer is A. if you notice the y-intercept, it its at -5
A is the only answer choice that gives -5 as the y-intercept
another way to make sure that A is the right answer is to calculate the slope
when you increase 3 units UP (y), you increase 5 units to the RIGHT (x)
since slope is y/x, it should be 3/5 which is also in A
another way to check A is to plug in points
hope this helps!
