Writing in Mathematics

Writing in Mathematics

When two quantities vary directly, the ratio of their values will always stay the same.

To solve a variation problem, you must first write the correct equation. All direct variation problems are solved using the equation y = kx. If it is a word problem, you should consider using variables that are relevant to the problem being solved instead of x and y for instance. Next, use the information presented in the problem to find the value of k or constant of variation or the constant of proportionality. The next thing to do would be to rewrite the equation by substituting in the value of k. Finally read and use the last bit of information that was given in the problem to answer the question.

When two quantities vary inversely, it means that the values of the two variables change in an opposite manner.

Combined variation describes the relationship between three or more variables that vary directly and inversely with each other. For example, if z varies directly with x and inversely with y, the following equation would be created: z = k (x/y)

Joint variation is much like combined variation in that it uses three or more variable but varies jointly with each variable. For example, if m varies jointly with p and q then we would get the equation: m = kpq, where k is a constant.

This equation shows an inverse variation because variables use division which shows that they are inversely related.

This equation shows a joint equation because z varies jointly with the constant as well as the two other variables.

The name Gravity Model is appropriate because both the model and joint variation are similar in that joint variation is when a variable varies directly as the product of two or more