Junior 2 math independent variable function, junior 2 math problem variable in function

Substitute the coordinates into it, the number in front is x, and the number in the back is y2The constant is (30), where the independent variable is (t), u) is a function of (t), and when t=(15), u=0

This test is a few definitions of functions, take a closer look at the definitions in the book.

3. If you are not familiar with functions, you can write a text version of the equation to substitute it.

For example, in this question, because the perimeter = edge + side + side you should be able to understand this.

Let's substitute the value, because the perimeter is y and one side is x, so there is.

y (perimeter) = 7 (edge) + 4 (edge) + x (edge).

Remove the text and have y=7+4+x=11+x

In the following question, the range of values of the independent variable x.

This refers to the number that x can take, because x is one side of the triangle, so it must not be negative, so it must be greater than 0, and know that the sum of the two sides in the triangle is greater than the third side, so x should be less than 7+4, and it should be greater than 7-4

If you still don't understand that, you can add me to talk about it.

1.Bringing the point coordinates into the function holds equivalently is the answer c

2.The constant is 30, the independent variable is t, and u is a function of t, and when t=15, u=0

3

1. C, substitute a few options into the function, and the one that matches it is C

2. The constant is 30, the independent variable is t, u is a function of t, t=15, just look at the concept of function.

3, y=11+x, 3 didn't expect me to do it, comedy.

2.The constant 30 independent variable t u is a function of t when t = 15.

3.y=4+7+x The value ranges from 3 x 11

s=l*(50-l)

Since the area is equal to the length times the width, l is the length of the side, and 100 divided by 2 gives half the length of the fence, which is also equal to l plus the width.

The constant is 50 and the variable is l.

If one side is long, then the other side is long(50-l), so the area s=l*(50-l);

The sum of the two sides 50 is a constant, and l, 50-l, and s are all variables.

Is that how you learn math ... I think so myself, not sure ...

The relation is s=l*(100 2-l); The variables are the side length l and area s The area s varies with the side length l, and the constant is the sum of the side lengths 100 or the sum of the length and width of the rectangular field 50

(1) In y=2*x 2+7, x takes any value, and the function is meaningful, so the range of x is r.

2) y=1 (x+2), the denominator is not zero, so the range of x is that x is not equal to -2.

3) y=(x-2) (1 2), the number of squares to be opened is required to be non-negative, so the range of x is x greater than or equal to 2.

In general, the intersection above means that x is greater than or equal to 2. That is, when x is greater than or equal to 2, the expressions of the previous function above are all meaningful!

The first x (-There are no special cases.

The second x (-no special cases.

The third x (2,+ Unless there are special cases, the number of the open root number can only be greater than 0.

Both the first and second x are real numbers, the third x > = 2 is enough, and the number under the even root sign cannot be negative.

x has no solution, the first equation y> =7 is brought into the equation 2, and 1 (x+2)> =7 gives x =2, so there is no solution.

y=2x 2+7 , x (-y=x+1 2 or y=1 (x+2) The former is x (-the latter, the denominator cannot be 0, i.e. x+2!). =0 i.e. x is not equal to -2

y=x-2 under the root number, the root number cannot be negative, that is, x-2 is greater than or equal to 0, and x>=2 is launched

The range of the first x is a real number, and the range of the second x is x!=-2 for all real numbers, and the range of the third x is x>=2

Answer: 1, y= x 3: is an integer, x takes a real number;

2. y=2 1 x: is a fraction, x takes: x≠03, y=x 2x 3: the same as 1,

4. y= 2x 3 : is a quadratic radical: 2x 3 0, x 3 2

The value range of the independent variable should be noted: (1) the denominator (not equal to the independent variable) cannot be zero, (2) the number of open squares under the quadratic root number (not equal to the independent variable) must be greater than or equal to zero, and (3) when the relation is an integer, the independent variable is the whole real number.

4) The practical situation should be combined in the application questions.

Hope you can figure it out for yourself!

The first two of i are both one-time functions, so the independent variables are real numbers, and the last two have root numbers, and the numbers under the root number must meet the condition of non-negative numbers.

y=2 1x-3 (x is a real number).

y=2-x 1 (x is a real number).

y=x-square+2x-3 (x>=0, so x is non-negative), y=2x-3 under the root number (2x-3>=0, so x>=3 20

（1）y=2/（1x-3）

x-3≠0，x≠3

So the value can be a total real number that is not 3.

2）y=2-x/1

All real numbers. 3) y=x-square+2x-3

All real numbers. 4) Y = 2x-3 under the root number

2x-3≥0

2x 3x 3 2, the value range is x 3 2

y=x/2-3

x ry=2-1 x or 1 (2-x).

The denominator is not equal to 0

x≠0 or x≠2

y=x^2+2x-3

x∈ry=√(2x-3)

The formula under the root number should be greater than or equal to 0

2x-3 ≥ 0

x ≥ 3/2

1)y=12-4*x

Argument. It's x

The callable absolute variable is y

of independent variables. The value is Fan Xian Min Wai.

is 02) y=

The independent variable is n, and the strain variable is y

The value range of the argument variables is as follows:

Positive integer. 3) It should be a rectangle, and the trapezoid only knows that one side cannot be found to destroy the chain branch.

The speed of a car can be calculated directly, and the square root of 300 * 5 = 1500 is less than 40

The speed of car B is a range, and the size of 4*10 is less than 4*12, so it is B speeding.

According to the meaning of the topic, the formula is y=10+

Because the weight of the load does not exceed 16 kg, we get x<=16