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
Step-by-step explanation:
f(x) = x² - 3x + 5
f(-2) = (-2)² - 3.(-2) + 5
f(-2) = 4 + 6 + 5
f(-2) = 15
Answer:
Sorry, don’t know that one ♀️
Step-by-step explanation:
Answer:
31.4
Step-by-step explanation:
3.14 x 2 x 5 = 31.4
