Understanding Direct and Inverse Variation

The video tutorial explains the concepts of direct and inverse variation, focusing on how to use equations to represent these relationships. It demonstrates finding the constant of proportionality (K) for direct variation, writing the variation equation, and calculating the value of Y for a given X using the direct variation equation. The tutorial provides step-by-step examples to ensure understanding.

What is the equation used for direct variation?

• y = K + X

• y = K / X

• y = K * X

• y = X / K

In a direct variation, if Y is 19.8 when X is 3, what is the constant of proportionality?

• 8.8

• 5.5

• 6.6

• 7.7

How do you find the constant of proportionality in a direct variation?

• Multiply Y by X

• Divide Y by X

• Add Y and X

• Subtract X from Y

What is the direct variation equation if the constant of proportionality is 6.6?

• y = 6.6 * X

• y = X / 6.6

• y = 6.6 / X

• y = 6.6 + X

If the constant of proportionality is 6.6, what is the equation for Y in terms of X?

• y = X / 6.6

• y = 6.6 / X

• y = 6.6 * X

• y = 6.6 + X

Using the equation y = 6.6 * X, what is Y when X is 8?

• 54.8

• 48.8

• 50.8

• 52.8

What is the result of 6.6 multiplied by 8?

• 52.8

• 51.8

• 53.8

• 50.8

In a direct variation, if X is doubled, what happens to Y?

• Y is tripled

• Y is doubled

• Y remains the same

• Y is halved

What is the relationship between Y and X in a direct variation?

• Y is directly proportional to X

• Y is inversely proportional to X

• Y is exponentially related to X

• Y is unrelated to X

If Y varies directly as X, which of the following is true?

• Y decreases as X increases

• Y is constant regardless of X

• Y increases as X increases

• Y is zero when X is zero