National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Standard Form of a Line
Dr. Math gives an inspiring and clear discussion about equations of lines and lines as functions. The Dr. discusses the benefits of the standard form of a line and prompts the student with an equation which can not be written in the...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Equation of a Line Parallel to an Axis
Dr. Math gives a short discussion on how to find the equation of a line parallel to an axis (, parallel or horizontal.)
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: When Is a Slope 0 or Undefined?
At this site Dr. Math gives a discussion on the slopes of lines. The Dr. gives an analogy between the slope of a line and walking up and down hills. The Dr. explores the concept of undefined and zero slopes through his response to a...