Download Lines, Lines, Lines

Lines, Lines, Lines
Due Monday, October 17
Name:
(1) Let’s say a line L1 is described by y = 2.54 · 10−1 x + 56.35. If a line L2 is perpendicular to
the line L1 , then what is the slope of L2 ? If L2 passes through the point (86.54, −32), then
what is an equation for L2 ?
(2) Write the equation for a vertical line that passes through the point (9, −8).
(3) A runner is traveling at a rate of 8 m
s and he runs away from his house at a constant speed.
If he starts running 50m from his house, write the rule for a function f that tells you the
runner’s distance from the house in meters as a function of time in seconds.
(4) Your impetuous friend, Wendell B. Slowe, is at it again. This time he is trying to solve the
following story problem.
A car is traveling toward Portland at a constant rate of 60mph. If the car starts 215 miles
away, how long will it take the car to reach Portland?
Wendell creates a function g for the position of the car, with time as the independent
variable, where
g(x) = 60x + 215.
He solves this equation, correctly, for x0 when g(x0 ) = 0 and gets
0 = g(x0 )
= 60x0 + 215
−60x0 = 215
215
x0 =
−60
x0 = −3.58.
Wendell is pretty sure the solution should not be a negative number. Explain to Wendell
what he did wrong and why it was incorrect.
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