Answer:
Identity (a) can be re-written as
which we already proven in another question, while for idenity (b)
step A is simply expressing each function in terms of sine and cosine.
step B is adding the terms on the LHS while multiplying the one on RHS.
step C is replacing the term on the numerator with the equivalent from the pithagorean identity 
The correct answer is the first option which is negative 2
Answer: x = 5/3
Step-by-step explanation:
To graph the equation, plot a few points then connect then with a line.
f(x) = 440 - 55x
Plug in numbers for x to get the y value.
f(0) = 440
f(1) = 385
f(2) = 330
f(3) = 275
f(4) = 220
f(5) = 165
So when you graph these points, the y intercept is y = 440 because the graph crosses the y axis at (0, 440).
The x intercept is where the graph crosses the x axis. This happens when y = 0.
0 = 440 - 55x. Solve for x.
55x = 440
x = 8
So the x intercept is x = 8
