Answer:
13. 0.145, 0.18, 0.206, 0.315
14. 1.75 times
<u><em>WARNING</em></u>
<em>im not completely sure sooo, Im really really sorry if you get it wrong</em>
8. complementary angles = 90°
3x+3+10x-4 = 90
13x-1 = 90
13x = 91
so x = 91/13= 7
then K = 3(7)+3 = 24°
so L = 10(7)-4 = 70-4 = 66°
9. P is three less than twice of Q
so P = 2Q-3
supplementary angles = 180°
P+Q = 180
(2Q-3)+Q = 180
3Q-3 = 180
3Q = 183
so Q = 183/3 = 61°
then P= 2(61)-3 = 122-3 = 119°
10. B is two more than three times of C so B= 3C+2
complementary angles = 90°
B+C= 90
(3C+2)+C=90
4C+2=90
4C= 88
so C= 22°
then B = 3(22)+2= 66+2 = 68°
Given:
cos 120°
To find:
The exact value of cos 120° in simplest form with a rational denominator.
Solution:
We have,

It can be written as

![[\because \cos (90^\circ-\theta)=-\sin \theta]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Ccos%20%2890%5E%5Ccirc-%5Ctheta%29%3D-%5Csin%20%5Ctheta%5D)
![[\because \sin 30^\circ=\dfrac{1}{2}]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Csin%2030%5E%5Ccirc%3D%5Cdfrac%7B1%7D%7B2%7D%5D)

Therefore, the exact value of cos 120° is
.
V=(4/3)(pi)(r^3)
r=7
Hope this’ll help
It’s A)5m+16 75 your welcome and if it’s wrong I don’t know why