MA 141 Turn in homework 3.6
Pitts SHOW YOUR WORK! Name _______________________
1. (#14) Find dy/dx by implicit differentiation. x2 + 5xy + y2 = 10. Show your work
2. (#26) Find dy/dx by implicit differentiation 2 2 3
x y x
x y
. (Hint: multiply both sides by LCD first.)
3. (Similar to # 32) Find an equation of the tangent line to the graph of the function 2 2
17y x at (1, 4).
Show your work. Leave the equation in slope-intercept form of a line.
4. (#34) Find an equation of the tangent line to the graph of the function 3
( 1)x y x at (1, -1). Show
your work. Leave the equation in the slop-intercept form of a line.
5. (#42) Suppose the quantity x of Super Titan radial tires made available each week in the marketplace
is related to the unit-selling price by the equation 21
48 2
p x where x is measured in units of a
thousand and p is in dollars. How fast is the weekly supply of Super Titan radial tires being introduced
into the marketplace when x = 6, p = 66, and the price/tire is decreasing at the rate of $3/week?
6. (#44) Suppose the wholesale price of a certain brand of medium-size eggs p( in dollars/carton) is related to the weekly supply x (in thousands of cartons) by the equation 625 p2 – x2 = 100. If 25,000 cartons of
eggs are available at the beginning of a certain week and the price is falling at the rate of 2
cents/carton/week, at what rate is the supply falling?
7. ( #52) Two ships leave the same port at noon. Ship A sails north at 15 mph, and ship B sails east at 12 mph. How fast is the distance between them changing at 1 p.m.?
8. Suppose that for a company manufacturing calculators, the cost and revenue equations (in $) are:
90, 000 30C x and 2
300 30
x R x , where the production output in 1 week is x calculators,
a.) Write the Profit equation.
b.) If production is increasing at a rate of 500 calculators per week when production output is 6,000 calculators, find the rate of increase (decrease) in the profit.