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 
f(x) = x²<span> - 5x + 1
f(-3) = (-3)</span>² - 5(-3) + 1
<span>
f(-3) = 25
</span>--------------------------------------------------<span>
Answer: f(-3) = 25 (Answer C)
</span>--------------------------------------------------
3.5x-10>-3 add 10 to both sides
3.5x>7 divide both sides by 3.5
x>2
... now for the other inequality:
8x-9<39 add 9 to both sides
8x<48 divide both sides by 3
x<6
So we have x>2 and x<6, so the compound inequality is:
2<x<6 and this means that the solution set is:
x=(2, 6)
<span>Any point in figure A can be mapped to a point in figure B.</span>
