Answers to Mathematical and Physical Equations Third Edition

1. When x> 1 is simplified.

Square of √(x+ 1/x) -4

2. The two adjacent sides of the parallelogram are 3 and 5, and the lengths of the two line segments divided by the acute bisector of the parallelogram are

3. Given that the four sides of a trapezoid are 1, 2, 3 and 4 respectively, the area of this trapezoid is

In quadrilateral ABCD, diagonal AC BD passes through point O, from (1) ab = cd; (2)AB is parallel to CD; (3)OA = OC； (4)OB = OD； (5)AC is perpendicular to BD; (6) The AC bisection angle is poor; Under these six conditions, it is concluded that the quadrilateral ABCD is a diamond. For example, (1)(2)(5)=ABCD is a diamond, and then write two that meet the requirements: _ _ _ _ _ _ _-ABCD is a diamond; _ _ _ _ _ _ _ _-ABCD is a diamond.

Second, multiple choice questions

1 1. as shown in the figure, BE=CF, AB=DE. Which of the following conditions can be added to derive △ ABC △ DFE ()?

(A)BC = EF(B)≈A =≈D(C)AC‖DF(D)AC = DF

12. It is known, as shown in the figure, AC=BC, AD=BD, and the following conclusion is incorrect ().

(a)co = do(b)ao = bo(c)ab⊥bd(d)△ACO?△bco

13. Take a point P in △ABC so that the distances between the three sides of the point P and △ABC are equal, then which three lines of △ABC should the point P intersect? ()

(a) The median line (d) of the bisector (c) with a high angle (b) is known as the median vertical line.

14. The following conclusion is correct ()

(a) Two right-angled triangles with equal acute angles are congruent; (b) A hypotenuse corresponds to the congruence of two equal right triangles;

15. The following conditions can determine that a set of △ ABC △ def is ().

(A)A =∠D，∠C=∠F，AC=DF (B)AB=DE，BC=EF，∠A=∠D

(C)∠A=∠D, ∠B=∠E, ∠C=∠F (D)AB=DE, and the perimeter of △ABC is equal to that of △DEF.

16. As shown in the figure, in △ABC, AB=AC, AD is the angular bisector, and BE=CF, how many of the following statements are correct ()?

(1)AD bisection ∠ EDF; (2)△EBD?△FCD； (3)BD = CD； (4)AD⊥BC.

1 (B)2 (C)3 (D)4。

Third, answer questions:

1. As shown in the figure, AB=DF, AC=DE, BE=FC. Q: Are Δ Δ ABC and Δ Δ def identical? Are AB and DF parallel? Please explain your reasons.

2. As shown in the figure, is it known that AB=AC, AD=AE, BE and CD intersect at the congruence of O, δδABE and δδACD? State your reasons.

3. As shown in the figure, AC and BD intersect at O and are equally divided by O. Can AB‖CD be obtained, and AB=CD? Please provide a justification for the answer.

As shown in the figure, point A and point B are two points on both sides of the lake. In order to measure the distance between point A and point B, please design a scheme to measure the distance between point A and point B, and explain the feasibility of your scheme.

Verb (abbreviation of verb) reading comprehension questions

19.8 class (1) went to other places to have a math activity class. In order to measure the distance between a and b at both ends of the pond, the following scheme is designed:

(1) As shown in Figure 1, firstly, take a point C on the flat ground that can directly reach A and B, connect AC and BC, respectively extend AC to D and BC to E, so that DC=AC and EC=BC, and finally measure the distance of DE as the length of AB;

(Figure 1)

(2) As shown in Figure 2, first pass through point B as the perpendicular BF of AB, then take two points C and D on BF to make BC=CD, then pass through point D as the perpendicular DE of BD, and pass through the extension line of AC at point E, then the length of DE is the distance of AB.

Second, multiple-choice questions:11-16: dabcad

Iii. Answer the question: 1. Yes; 2. Yes, the reason is slight; 3. Triangle congruence; leave out

Fourth, reading comprehension questions:

(1) Yes; (2) Yes; (3) Constructing triangular congruence energy

If the sum of two natural numbers is 100, the maximum value of the product of this number is _ _ _ _ _

From 1: 45 to 2: 05, the corner of the minute is _ _ _ _ _

If the complementary angle of an angle is x0, the complementary angle of this angle is _ _ _ _ degrees (900 < x0 < 1800).

There are two charging methods for mobile phones in the province: (1) Xiaoyingtong's monthly phone bill 10 yuan, plus 0.4 yuan's phone bill every minute; (2) The monthly phone bill of "Shenzhouxing" is 25 yuan every month, plus 0.2 yuan phone bill every minute. If a mobile phone user estimates that the monthly call time is about 150 minutes, he should choose _ _ _ _ _ _ _.

Arrange positive even numbers into 5 columns according to the following table:

Column 1 column 2, column 3, column 4 and column 5

The first line 2 4 6 8

The second line16141210

Line 3 18 20 22 24

The fourth line 32 30 28 26

…… … … … …

According to the rules in the table, even number 2004 should be in row _ _ _ and column _ _ _.

x2 xm_________=x2m + 3，(0.25 a)2(4 B2)2 = _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Use the multiplication formula to calculate199× 201= (_ _ _ _ _ _ _ _ _) (_ _ _ _ _) = _ _ _ _ _.

Expressed in scientific notation:-0.0000203 = _ _ _ _ _, 5720000 = _ _ _ _ _.

If (2x-5)-5 is meaningful, then the condition that X should have is _ _ _ _ _ _ _.