Where can you tell if it is proportional or not

Proportional. Understanding the proportional relationship is taught by studying the law of change between the three quantities in the relationship between the total number and the number of copies. Contains three quantities in the total vs. number of copies relationship:

The total number, the number of copies, the number of copies. When the number of copies per serving is constant, the total number and the number of copies are two related quantities. When the number of servings expands (or shrinks) by several times, the total number also expands (or shrinks) by the same multiple.

Or the total number increases (or decreases) by several times, and the number of copies expands (or decreases) by the same multiple. Similarly, when there is a certain number of servings, the total number is the amount associated with the number of servings per serving. The number of copies increases (or decreases) by several times, and the total number increases (or decreases) by the same multiple.

If the total number increases (or shrinks) by a factor of several times, the number of copies per copy also expands (or shrinks) by the same multiple. The total number of copies with this variation is directly proportional to the number of copies (or servings) per copy.

If two quantities are proportional, then the ratio of any two numbers of one quantity is equal to the ratio of the two corresponding numbers of the other quantity. For example, if a train has a certain speed, the travel time is proportional to the distance. The time ratio is 1 2, and the corresponding distance ratio is 60 120 = 1 2.

If two quantities are proportional, the ratio of any one of their pairs to the corresponding numbers is certain. For example, the travel time of a train is proportional to the distance, and the ratio of the distance corresponding to the time is certain: 1 60 = 2 120.

A sufficient and necessary condition for two quantities to be proportional: if quantities A and B are proportional, their corresponding values are denoted by x and y, respectively. Then quantity a is directly proportional to quantity b.

is a variable.

One quantity changes with the change of the other, one quantity expands and the other expands, one quantity shrinks and the other shrinks.

Proportionality refers to two related quantities, one quantity changes, and the other quantity also changes with it. If the ratio of the two corresponding numbers in these two quantities is constant, these two quantities are called proportional quantities, and their relationship is called proportional relations.

Expressed by letters: If the letters x and y are used to denote two related quantities, and k is used to denote their ratio (certainly), the proportional relationship can be expressed by the following relation: y: x=k (a certain amount).

What is the relationship between the area of a rectangle and its length and width: the area divided by the other side equals that side.

The relationship between positive and inverse proportions is as follows:1. Similarities.

1. There are two variables in the relationship between things, one quantitative.

2. In two variables, when one variable changes, the other variable also changes.

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

2. Mutual transformation.

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

The above content refers to Encyclopedia - Proportional.

The above content refers to Encyclopedia - Positive Proportional and Inverse Proportional.

Listen to me: first understand what is meant by "proportionality", such two quantities: one of them expands (or shrinks) the source dust by many times, and the other expands (or shrinks) the same times.

These two quantities are proportional. For example, when time is constant, the speed is proportional to the distance. Let's talk about "proportionality".

Two proportions are proportional if they are on an equation. For example, 2 pens are 8 yuan, how much are 7 pens? There's the equation:

2:7=8:x (this is the proportion), solve this ratio:

x=7*8 2=28 (yuan) The person who answered above confused "proportional" and "proportional", "ratio" and "proportional", and "ratio" is the relationship between two numbers. "Proportion" is the relationship between four numbers. There is no equation for "than".

There is a ratio. "Proportion" is the equation, which is two ratios. It is an equation for two hailstones to judge a ratio.

Do you understand?

Elementary school math formulas about proportionality:

Distance: Time = speed (certain), distance and time are proportional.

Workload: Working time = work efficiency (certain), workload and working time base type are proportional.

Total price: quantity = unit price (certain), the total price is proportional to the quantity.

The distance on the diagram is disproportionate: the actual distance = scale bar (certain), and the distance on the diagram and the actual distance are proportional to the bucket pin.

Characteristics of proportionality:

1. When the value of x in the inverse proportion, the value of the independent variable is also converted into its reciprocal, and the inverse proportion is transformed into positive proportionality. When the value of x in a positive proportion (the value of the independent variable) is converted to its reciprocal, the positive proportion is converted to an inverse proportion.

2. The proportional image is on a ray that passes through the origin. It is from the intersection of the abscissa and ordinate of the statistical table along the diagonal line from the lower left corner to the upper right corner, extending to the outside of **, where it can extend downward in the sense of proportionality, so it is considered a straight line.

Positive proportionality means that the relationship between two variables is directly proportional, that is, when the value of one variable increases (or decreases), the value of the other variable increases (or decreases) in the same proportion. It is usually expressed as:

y = kx

where y and x are two variables, and k is the proportionality constant. In this formula, the ratio of y to x is constant, and when x doubles, y doubles as well; When x is doubled, y is also doubled. Therefore, the relationship between y and x is proportional.

For example, when we are buying a commodity, the relationship between the crack rate of the commodity and the amount of the quantity is usually proportional. If the ** of the product is 10 yuan each, then the total price of buying 2 goods is 20 yuan; If you buy 4 items, the total price is 40 yuan, and the ratio between the two is constant.

Proportional. When one quantity increases, the other quantity increases in proportion to the same amount is called positive proportionality.

For example, u = i r, when i is constant, r doubles, u also doubles, u is proportional to r.

Proportionality is when the dependent variable changes with the change of an independent variable, and the ratio of the dependent variable to the independent variable is a constant, such as:

y k* x where k is a constant, y is proportional to x, because there is y x k (the ratio is constant). It should be pointed out that in y k* x the two variables are proportional, and y k* x b (k and b are constants) cannot be said to be proportional to y and x, because y x is not a constant.

If one number is expanded by how many times, the other number must also be expanded by how many times 0. Or zoom out. Here's an example. If his productivity is the same, then regardless of the total amount of work and hours it has worked? He's all proportional.

How to tell if two quantities are proportional 1. To determine whether two quantities are related, two unrelated quantities cannot be proportional. 2. It is necessary to determine whether the ratio (i.e., quotient) of the two numbers corresponding to the two related quantities is certain. Therefore, according to the meaning of proportionality, it can be judged by the quantitative relation.

For example, is the circumference of a circle proportional to its diameter? Because the ratio of the circumference of a circle to its diameter is constant:

The circumference of the circle diameter = pi ( ) certain), so the circumference of the circle is proportional to the diameter Another example: Is the area of a square proportional to the length of the sides? Because the ratio of the area of the square to the length of the sides is an indeterminate value:

The area of the square Side length = Side length So the side length of the square cannot be proportional to the area.