We expand first (cos x +cos y)^2+(sin x-sin y)^2:
= cos^2 x + 2 cos x cos y + cos^2 y+ sin ^2 x + sin ^2 y - 2 sin x sin y
= (cos^2 x + sin ^2 x) + (cos^2 y + sin ^2 y) + 2 (cos x cos y - sin x sin y)
then, apply the trigonometric identities of addition and summation of angles
= 1 + 1 + 2 cos (x+y)
we add the following identities above that results to
2 + 2 cos (x+y)
Answer:
ITs C One solution
Step-by-step explanation:
Two sides are not equal.
Given
Your family has a circular swimming pool.
The radius of the pool is 9 feet and and its depth is 4 feet.
Find out the volume of the pool.
To proof
As depth is given in the question that means the shape of the swimming pool
is cylinder.
Formula
where r = radius
h = height
now
radius of the pool is 9 feet and and its depth is 4 feet.
put all the values in the above equation
we get
use 3.14 to approximate pi
we get
= 1017.4 ( approx )feet²
Hence proved
Answer:
okay so you multiply the price of the snakes by how much he bought which is $5.00 so you can subtract $5 - $8 and you get $3.00 so that is how much is left over. Now you want to divide $3.00 by 2 and now you get $1.50. So each soda costed $1.50
Answer: 8
Step-by-step explanation: