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 
Answer:
A)3
Step-by-step explanation:
Answer: He paid
for the T.V.
Step-by-step explanation:
We need to analize the information provided:
- The original cost of the T.V. was $599.99
- Joseph buys it at 35% off the original cost.
Let be "x" the amount Joseph paid for the T.V.
We can calculate "x" with the following expression:

Therefore, he paid
for the T.V.
Answer:
Percent increase is 17.6%
We still have to pay 7.50 with the coupon
Step-by-step explanation:
Percent increase = (new- original)/original *100%
= (10-8.5)/8.5 * 100%
= 1.5/8.5 * 100%
= 17.6470588%
Round to the nearest tenth
17.6%
This is an increase since the cost went up.
If we have 25% off, we still have to pay (100%-25%) = 75%
10 *.75 = 7.50
We still have to pay 7.50 with the coupon