Answer:
cos 4u = co^s2 2u - sin^2 2u
Step-by-step explanation:
cos 4u = co^s2 2u - sin^2 2u
Let 4u = 2x
cos 2x = cos^2 x - sin^ 2 x
cos (x+x) = cos^2 x - sin^ 2 x
Using cos(x+y) = cos(x)cos(y) -sin(x)sin(y)
cos(x) cos(x)- sin(x) sin (x)= cos^2 x - sin^ 2 x
cos^2 (x) -sin^2 (x) =cos^2 x - sin^ 2 x
Since this is true
cos 2x = cos^2 x - sin^ 2 x
This is true
Substituting 4u back for 2x
cos 4u = co^s2 2u - sin^2 2u
This is true
You have to decide all sides to figure out all the kissing pieces
Answer:
the question is confusing but the answer is 2010
Step-by-step explanation:
because in the year 2000 it was
260
then increased by
60
over 5 years making the next class
320
then in 2010 it was
400
and 320 + what is 400?
80
so the answer is:
2010
Answer:

Step-by-step explanation:
Collect like terms and calculate the sum