1, the circumference of a circle always changes with the diameter.

2. The area of square and rectangle varies with the length of length and width.

When walking, the speed is constant. The more time you spend, the longer you walk.

Second, the inverse proportion example

1, the cake area is certain, so the score is inversely proportional to the area of each cake.

2. Running 100 meters, running speed is inversely proportional to time.

Third, an example of disproportion.

1. The surface area and volume of a cylinder are out of proportion.

2. The circumference of a rectangle is fixed, and the length and width are not inversely proportional.

3. Laying floor tiles for a conference room, the side length of the floor tiles is out of proportion to the number of required floor tiles.

Extended data

Correlation between positive ratio and negative ratio

I. Similarities

1, the relationship between things has two variables, one is quantitative.

2. Among these two variables, when one variable changes, the other variable will also change.

3. The product or quotient of the corresponding two variables is certain.

Second, mutual transformation

When the value of x in inverse proportion (the value of independent variable) is also transformed into its reciprocal, it is transformed from inverse proportion to positive proportion; When the value of x in a positive proportion (the value of independent variable) is transformed into its reciprocal, it is transformed from a positive proportion to an inverse proportion.

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