Joint Variation.
Jointly Proportional. When we say z is jointly proportional to a set of variables, it means that z is directly proportional to each variable taken one at a time. If z varies jointly with respect to x and y, the equation will be of the form z = kxy (where k is a constant). Equation: c = 5ab.
Example 1
If y varies jointly as x and z, and y = 12 when x = 9 and z = 3, find z when y = 6 and x = 15. Step 1: Write the correct equation. Joint variation problemsare solved using the equation y = kxz. Step 2: Use the information given in the problem to find the value of k.
Joint Variation.
When we say z is jointly proportional to a set of variables, it means that z is directly proportional to each variable taken one at a time. If z varies jointly with respect to x and y, the equation will be of the form z = kxy (where k is a constant).