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
I'm assuming the equation is x^3 = 216 or

(both mean the same thing)
If so, then the solution to x^3 = 216 is
x = 6
<span>We can find this by taking the cube root of both sides
</span>x^3 = 216
x = 216^(1/3) .... 1/3 power means cube root
x = 6
Checking the answer:
x^3 = 216
6^3 = 216
6*6*6 = 216
216 = 216
Answer is confirmed
So once again
the answer is x = 6. This is assuming the initial assumption made at the top of the problem holds up.
Answer:
$25.10
Step-by-step explanation:
lunch=$7.52
dinner=$9.74
breakfast=$5.16
money left=$2.68
make total money he began with ‘x’
to find the total money he began with it will be
x-lunch+dinner+breakfast=money left
x-$7.52+$9.74+$5.16=$2.68
x-$22.42=$2.68
x=$2.68+$22.42
x=$25.10
Answer:
8/27 is represented in decimal as 0.2962962963
Answer:
Step-by-step explanation:
x+(-56)=12
exclude "x"
x=56+12
x=68