Inverse Variation
As the price of an item increases, its sales decrease. This is an example of inverse variation. An inverse variation problem has one constant of variation, but is divided instead of multiplied.
Solving Quadratic Equations by Factoring
A quadratic equation in which the quadratic trinomial has a leading coefficient of one can be solved by factoring. An example is given that also utilizes the zero factor property.
Solving Equations That Include Rational Expressions
To solve an equation with a rational expression, rewrite the equation to get rid of the fractions then solve the new equation. The same process is used to solve linear equations that contain rational expressions. If the solution makes any denominato...
Practical Problem: How Fast Can Two Workers Mow a Lawn?
A practical problem compares the rate at which two park workers mow the lawn and asks how much lawn the two can mow in an hour. The question is answered by adding rational expressions.
Solving a Quadratic Equation Using the Quadratic Formula
Quadratic equations that cannot be solved by factoring or the square root method can be solved using the quadratic formula. When an equation is in standard form, the values of a, b, and c, including their signs, can be substituted for the letters in...
Practical Problem: Calculate the Children's Dose of a Medication
Using a rational expression to solve a practical problem involving calculating the dose of a liquid medication for a child, given the adult dose and Young's rule.
Practical Problem: Finding the Amount of Electrical Current
Evaluating a rational expression to find out why a fuse keeps blowing out. Using the formula to find the total resistance of a parallel circuit.
Practical Problem: Threshold Weight
Direct variation is used in a practical problem to find the threshold weight for men of different heights.
Finding the Length of the Third Side of a Right Triangle
The Pythagorean Theorem can also be used to determine the length of the hypotenuse given the length of the legs, or the length of a leg given the length of the hypotenuse and the other leg. The formula is demonstrated for both purposes.
Midpoint Formula, The
The midway formula can be used to find the coordinates of a point that is half way between two given points.