Problem Sheet #4 (1.5-1.7)
ClassID: _____ Name: _________________________ Hmk. 4 Score _________
Math 1090 – 001 Spring 2013
Instructor: Katrina Johnson
Complete each problem. No credit will be given without supporting work.
1. True or False. Explain your answer.
a) A relation with two y-intercepts is a never a function.
b) A relation with two x-intercepts is never a function.
2. Given h(x) = x +1 − 3 . Find h(-6).
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3. Given g(x) = −2x 2 + 4 . Find g(x-3). Write your answer as a polynomial in standard form.
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4. Find the domain of each function.
a) f (x) = x + 3 − 2
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EC: What is the range of f?
b) g(x) =
3x − 2
x + 4x −5
2
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c) h(x) = 1 − 4 x
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5. A company will be marketing youth sports uniforms and found that if the cost of a uniform is
$40 then there should be approximately 3,000 uniforms purchases and that if the cost of a uniform
is $120 then there should be approximately 600 uniforms purchased. The company is willing to sell
these uniforms at a price of $50 if 900 of the uniforms could be sold, but would sell these for $90
if only 4,500 could be sold. Write the supply and demand equations. Then find the equilibrium point
for this market.
supply equation: ____________________________
demand equation: ___________________________
Equilibrium Point: ______________
6. A donut shop has fixed costs of $165 per day and variable costs of $0.10 per donut.
The shop sells the donuts for $0.63 each.
a) What is the cost function, C(x)?
b) What is the profit function, P(x)?
c) What is the marginal profit, MP?
d) How many donuts must be sold to break-even?
7. Graph the solutions of the system of inequalities. Be sure to clearly label your graph.
⎧ x − y < 3
⎨
⎩2x − y ≥ 3
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