Junior high school math masters teachers enter, ask junior high school math masters

I think it should be vertical, you take a closer look at the question, the question is about the position relationship of the plane Cartesian coordinate system, the question has clearly pointed out that it is the vertical relationship on the plane, so here I choose vertical!

As for the textbook you said, it is also correct, the x, y axes are originally two straight lines, and the position relationship between the two straight lines in the plane is only intersecting and parallel.

The main thing I want to explain in this question is what is the angle of the two axes of the plane Cartesian coordinate system, which is only 90 degrees, vertical!

It's a simple question, you have to pay attention to the review of the question, and don't complicate the simple question! If you choose to intersect, you can also do it, but that is equivalent to me asking you to live in **, and you say you live on the earth!

The plane has been clearly stated here, so there is no need to consider the position relationship of the straight line on the opposite plane!

Let's choose intersect, since the positional relationship is only intersecting, parallel, originally the plane Cartesian axis is in a plane, they are perpendicular, of course, intersecting, the orangutan will also choose the banana, and the monkey will also.

Write vertically more accurately! After all, vertical is a special case of intersection, and it is more accurate to write vertical intersection, but it seems too blunt, so it is better to write vertical!

Perpendicular is a special case of intersection, that is, the intersection angle is 90 degrees, if it is chosen, the most correct (vertical) is chosen

2 straight lines are intersecting and parallel!

The x-y axis is vertical!

Sometimes there are mistakes in the printing of textbooks! Don't worry too much about it.

That's supposed to be intersecting

There's a similar look here

Perpendicular can also be a straight line on a different plane.

The original question is organized as follows (solution) as shown in the figure, it is known that the three vertices of abc are a(2,3), b(3,1), c(-2,-2) (1) please make abc in the figure about the axisymmetric family graph of the straight line x=-1 def (the corresponding points of a, b, and c are d, e, f, respectively), and directly write the coordinates of the argumentative posture d, zhaofeng e, f; (2) Find the area of the quadrilateral abed

x2+4x is a rational number with a file, so the roll section x2 --- irrational number, (x-1) (x+3) - irrational number, the first (x+1) 2 --- irrational number, (x-1) 2 --- irrational number.

1, the square of a -1 a+1 is a fraction, and it should be "a-1 and a is not equal to -1".

Reducing the common factor of the numerator and the denominator of a fraction (a number that is not 1) is called reduction, and some fractions are still fractions after reduction, and some become integers, so just now he was only reduced, but he is indeed a fraction.

2. Fake fractions are usually used before the root number, no need to bring fractions, I have never seen that kind of writing printed on the book, so you don't write like that, fake fractions are used in calculations after high school, and there is almost no need to bring fractions, so it is recommended that you get used to using fake fractions.

In the first question, because the denominator is not 0, a is not equal to -1, you can write a-1, but be sure to indicate the range of a.

The second question is a little incomprehensible, is it 2 * root number 3, in order to avoid these problems, you can first resolve the problem is not the root number is equivalent to So you can write this first when you encounter problems in the future, and merge it is not 6

The root number of the third question can be carried in the root number. But some can be decomposed, 5 + root number 7, I feel that it is okay, but some are not, such as 3 + 2 root number under the root number, he can be transformed into root number 2, root number 2 + 3

Hope it works for you.

The second question? Ask the right question, the right one, you look at why.

Question: So there are two answers to this question?

Thank you for your question, senior.

1. Not necessarily, because if a=-1, it is not. If a is not equal to -1, then it is reduced to 1-a.

2. Try not to bring fractions True fractions or false fractions are okay before the root number.

3、ok！No problem. My math teacher said that.

Let me ask you, are you in the third year of junior high school? I am, I've just learned this. Now that I've learned quadratic radicals, can I make a friend?

1. Simplification cannot be carried out, because there is a defined field in the fraction, that is, a is not equal to -1, which is a condition, and simplification is no longer a condition.

2. In general, it is not written like this, because it does not conform to the principle of score formatting.

3. There can be a root number in the root number when doing the operation.

(1) No, to determine that a number is a fraction, you need to simplify it first, it is a-1

2) No, you can't. 3) Yes.

1.It can't be simplified, it's the way.

2.The root number should be preceded by an integer.

3.Of course.

1 cannot be simplified a=-1, the formula is meaningless.

2 Yes 3 Yes.

If you don't understand, you can ask again, see**.

Connecting OC to Hg to P solves all the problems.

1) ODCE is a rectangle, EH=HG=GD, so P is the midpoint triangle of HG, EHC is congruent with OGD, so HC is parallel to OG, and the same proves OH parallel GC, which can be proved.

2) cd, dg is obviously changing, so only consider cg, it's too late, sleep, continue to do it next time you have time, ps: cg ed is obviously not right, the reason is very simple, just give a counterexample, when c is at the midpoint of the arc ab.

Equal to 5 to the 2nd power.

1 out of 25 is the formula.

Hope to help. If you have any questions, please hi

The reciprocal of the power of -5 is 1/25

Of course, it can't be equal to 0, this topic says that at the beginning a and m points coincide, y means area, if x is equal to 0, then y is also equal to zero, according to the title meaning area is generated after movement, so of course x is not included is equal to 0. The detailed answer is shown in the figure, and it will not be possible to ask questions, and it is not easy to write satisfactorily and hope to adopt,