Step-by-step explanation:
km to m
1 km = 1000 m
2km = 2000 m
2000 : 800
20:80
answer: 1:4
![sin(\frac{7\pi}{2}) = -1\\y = sin(\frac{7\pi}{2})\\y = -1](https://tex.z-dn.net/?f=sin%28%5Cfrac%7B7%5Cpi%7D%7B2%7D%29%20%3D%20-1%5C%5Cy%20%3D%20sin%28%5Cfrac%7B7%5Cpi%7D%7B2%7D%29%5C%5Cy%20%3D%20-1)
I have attached the graph
Answer:
Similarly, the distance between two points P1 = (x1,y1,z1) and P2 = (x2,y2,z2) in xyz-space is given by the following generalization of the distance formula, d(P1,P2) = (x2 x1)2 + (y2 y1)2 + (z2 z1)2. This can be proved by repeated application of the Pythagorean Theorem.
Step-by-step explanation:
Use a calculator
Cos x = -12/13
sin x = -sqrt(13^2 - 12^2) / 13 = -5/13
tan x = 5/12
tan x/2 = (1 - cos x) / sin x = 1 - (-12/13) / -5/13 = 25/13 * -13/5 = -5
2sin^2 x/2 = 1 - cos x = 1 - (-12/13) = 25/13
sin^2 x/2 = 25/13 / 2 = 25/26
sin x/2 = 5/√26
sin x/2 / cos x/2 = tan x/2
cos x/2 = sin x/2 / tan x/2 = 5/√26 / -5 = -1/√26
sin x/2 = 5/√26
cos x/2 = -1/√26
tan x/2 = -5