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Selected answers to common questions:
Direct and indirect variation.
Slope, slope-intercept, standard form.
- Two Slopes, and Two Ways to Average Them [01/06/2016]
An adult has questions about the validity of a colleague's simple
method to average slopes — and about simplifying his own, more
involved approach. With sketches, trigonometric identities, and
conjugate products, Doctor Peterson explains the methods, and shows
- Types of Linear Systems [10/13/1997]
What is meant when a type of linear system is said to be a consistent or
an inconsistent system?
- Understanding Parametric Equations [04/02/1998]
Can you explain the basic principles of parametric equations?
- Units for Inverse Quantity [9/10/1996]
I have a graph of time vs. 1/distance. What units do I use for 1/
distance - cm^-1?
- Uses for Parametric Equations [04/23/1998]
What is a parametric equation used for? Can you give me an example?
- Using Cardan's Formula to find Real Roots [04/13/2000]
How can I show that, although the cubic equation x^3 - 6x = 4 has three
real solutions, Cardan's formula can find them by subtracting appropriate
cube roots of complex numbers?
- Using Descartes' Method of Tangents [10/2/1995]
Given a point P(3,9) on a parabola y=x^2, how do I find the slope of the
tangent to the parabola at point P using Descartes' method of tangents?
- Using Graphs to Solve Problems [12/29/1996]
How do you use graphs to find the answers to questions?
- Using x-Intercepts to Sketch Parabolas [08/04/2002]
How does knowing the x-intercepts of a parabola help me sketch it?
- Variation Per Unit of Time [02/22/2002]
Why does the slope of a line correspond to the space that the particle
runs per unit of time?
- A Way to Remember What 'm' and 'b' Mean in Slope-Intercept Form [02/01/2004]
An interesting memory trick to help you remember how to graph a linear
equation in slope-intercept form.
- What We're Doing When We Do Algebra [03/25/2002]
How do you graph x + y = 5 on a graph sheet?
- Write in Slope-Intercept Form [11/06/1997]
Write and sketch x - y + 2 = 0 .
- X- and Y-Intercepts [09/15/1998]
I'm having a hard time finding out how to solve an equation and then do
the graph. The intercepts confuse me also...
- X Line in a 3D Graph [03/10/2001]
Which is the x line - vertical or horizontal?
- X = TanX [03/21/2001]
Show that x = tanx has an infinite number of solutions.
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