2. Notation and Algebra of Functions
Exercise. B. Simplify the following expressions
with the given functions.
x–1
f(x) = 3 + 2x g(x) = –x2 + 3x – 2 h(x) = x–2
23. f(2a) 24. g(2a) 25. 2g(a) 26. h(2a)
27. 2h(a) 28. f(3 + b) 29. g(3 + b) 30. h(3 + b)
31. f(3 + b) – f(b) 32. g(3 + b) – g(b) 33. h(3 + b) – h(b)
34. f(3 + b) – f(3 – b) 35. g(3 + b) – g(3 – b)
36. g(x) + 3f(x) 37. 2g(x) + [f(x)]2 38. g(x) / h(x)
39. a. Peanuts cost $9.00/box, what is the cost of x boxes of peanuts?
b. Cashews cost $12.00/box, what is the cost of x boxes of cashews?
c. Let x = the number of boxes in one order. We have coupons for $7
off for one order of x boxes of peanuts.
What is the cost P(x) for x boxes peanuts with the coupon?
3. Notation and Algebra of Functions
c. Let x = the number of boxes in one order. There is a surcharge
(special tax) of $5 per cashew–order for x boxes of cashews. What is
the cost C(x) for an order of x boxes cashews?
d. Let x = the number of boxes in one order.
Simply 2P(x) + 3C(x). What does this function represent?
40. Recall that the area of a circle is A = π * r2.
A circle city of radius r = 5 km is expanding outwardly with the
radius of the city increasing at a rate of 2 km every year.
Let x = the number of years,
a. what is the radius r(x) of the city after x years?
b. after 10 years, what is r(10)?
what is the area when x = 10?
c. what is the area A(x) of the city expanding
(2 km/yr) r=5 km
after x years?
d. what is A(6)? A(8)? A(8) – A(6)?
What does each expression mean?