Math 115  Lab #3
M. Flashman

I. Lines
II. X and Y intercepts for functions

I. Lines and Linear Functions.

Demonstration with Winplot.
• Plot a function :explicit... y = f (x)...
• f(x) = 2x-4
• f(x) = mx + b "Slope: m Y-intercept:(0,b)"
[ Illusrate use of parameters.]
• f(x) = m(x-a) + b "Point:(a,b)  Slope:m"
• Find Y and X intercepts. [ x= 0... y = ?; y = 0... x = ?]
• Plot a Line: ax + by = c
• Example: a = 2;   b = 6;  c = 4.
• If b = 0 then line is vertical!
• If a = 0 then line is horizontal.
• Anim Menu: A, B, C, ...
• library: for reference.
• User functions...
• The Inventory : Inventory... Ctrl  I
• Table for f(x)

II. X and Y intercepts for functions
Record your answers for the next work and submit them on Moodle by Wednesday, Sept.12.

Use Winplot to find the Y- intercept and any (and all) X-intercepts  in each of the following:
• y = -5x2 - x + 6 .
• y = -x2 + 4x + 3 .
• y = 2x3 - 5x2 - x + 4 .
• y =  x3 + 5x2 - 2x - 4 .

• Slider...
• function choice
• the "slider" [used for tracing and finding values of f(x).]
•   Zeros...   Save as...

End of Lab 3