Math 10Lesson #2

Inverse Variation

Mrs. Goodman

Inverse Variation

y = k/x

k is the constant

y is inversely proportional to x

Inverse Variation

What would this relationship look like if we solved the equation for k?

Graph of Inverse Variation

Inverse Variation

How could we describe the inverse variation

relationship in our own words?

Inverse Variation

As one variable INCREASES, the other variable…..

Example

The amount of time it takes for an ice cube to melt

varies inversely with the temperature

Example

a) How could we write an equation to represent

this relationship?b) If it takes 4 hours to melt one block of ice at

52 degrees, find the value of k.

Direct vs. Inverse

X 5 10 20 40 80 160

320

Y 4 8 16 32 64 128

156

X 25 50 60 100

150

Y 8 4 3.33

2 1.33

Direct vs. Inverse

Which table of values represents direct variation and which table of values

represents inverse variation?

Ideas

Can you think of other real life examples of inverse

variation?

Reflection Questions

y = k/x

1)How will the value of y change as x increases?

2)If the value of x doubles, how will the value of y

change?

That’s all for today!

Thanks for working hard!

See you next time!