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
A rectangular prism is defined by three lengths.
We can find out how many unit cubes would be in a prism by multiplying these three lengths together--that's how we find our <em>volume</em>.
Similarly, we can come up with different ways to multiply together three different numbers and make 18.
Each combination would be a new rectangular prism, with one catch:
Order doesn't matter. A prism with lengths 2, 2, and 3 is the same as one with lengths 2, 3, and 2, so don't make that mistake.
To find each combination, keep splitting 18 in different ways.
If one of the ways we split it can also be split, we need to write out that, too.
Here are the possible combinations:
18 × 1 × 1, obviously
9 × 2 × 1. splitting off 2
6 × 3 × 1. splitting off 3
4 × 6 × 1. our next biggest we can take out is 6, which can also be split...
4 × 3 × 2. there's the split of 6 into 2 and 3
<em>(3 × 6 × 1 is a repeat.)</em>
3 × 3 × 2 is new, though
<em>(2 × 9 × 1 is a repeat...)
</em><em>(2 × 3 × 3 is a repeat...)
</em>(aaaand 1 × 1 × 18 is a repeat. let's count up our combinations.)
<em>
</em>
There are 6 possible ways to multiply numbers together and get 18...
So 6 possible rectangular prisms.
Answer:
1/50000
Step-by-step explanation:
Sorry if this wasn't helpful! this was the only logical answer i had!
It can maybe be um 3 times 17 55 um maybe 88
-6b > 42 = b<-7
or
4b > -4 = b>-1
Hope this helps.
