Answer:
The most straightforward way to obtain the expression for cos(2x) is by using the "cosine of the sum" formula: cos(x + y) = cosx*cosy - sinx*siny. cos(2x) = cos² (x) - (1 - cos²(x)) = 2cos²(x) - 1. = 2cos²(x) - 1.
Step-by-step explanation:
(72/80)x90=81
Divide seventy-two by eight and multiply it Ninety.
Answer:
Step-by-step explanation:
To find the inverse of a function, simply 'switch' the x and y's and solve for y. 
becomes 
. Now, solving for y, we get .
hope this helped! :)
