Direct & Inverse Variation Calculator
How It Works
This direct & inverse variation calculator uses established formulas to provide accurate results.
The basic rule:
- Direct variation: y = kx where k = y/x
- Inverse variation: y = k/x where k = xy
- k is the constant of variation (proportionality)
Results are estimates. Consult a professional for critical decisions.
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Explore Allday Everyday Math →Frequently Asked Questions
What is direct variation?
Direct variation means y = kx. As x increases, y increases proportionally. If you double x, you double y. The graph is a straight line through the origin. Example: distance = speed × time (at constant speed).
What is inverse variation?
Inverse variation means y = k/x. As x increases, y decreases. If you double x, y is halved. The graph is a hyperbola. Example: speed = distance/time (for a fixed distance).
How do I find the constant of variation?
For direct variation: k = y/x. For inverse variation: k = x·y. Use any known pair of (x, y) values to calculate k, then use it to find unknown values.
How can I tell if a relationship is direct or inverse?
If both variables increase together, it is likely direct. If one increases while the other decreases, it is likely inverse. Check: if y/x is constant, it is direct. If x·y is constant, it is inverse.