Given three points a (- 1,2), B (3,4) and C (- 2,5), the equation of a line passing through a point a and a line passing through B. C is obtained

Given three points a (- 1,2), B (3,4) and C (- 2,5), the equation of a line passing through a point a and a line passing through B. C is obtained

Given three points a (- 1,2), B (3,4) and C (- 2,5), the equation of a straight line passing through point a and perpendicular to the line passing through two points B and C is obtained
The slope of the straight line where BC is located is k = (5-4) / (- 2-3) = - 1 / 5, so the slope of the straight line passing through a and perpendicular to BC is K & # 8321; = 5;
The equation is y = 5 (x + 1) + 2, that is, 5x-y + 7 = 0

The linear equation passing through a (- 2,5) and parallel to B (- 1, - 3) C (- 1, - 3)

kBC=0
The linear equation y = 5 passing through a (- 2,5) and parallel to B (- 1, - 3) C (- 1, - 3)

According to the following conditions, the equation of a straight line is obtained and transformed into a general formula. The passing point (- 4, - 5) is parallel to the y-axis

x+4=0

Battery charging is to convert electrical energy into chemical energy. Using the electricity in the battery is to convert chemical energy into electrical energy. How to understand that?

It's a transformation of energy. It's easy to understand

The application of mathematical problems in real life

A random survey is conducted among 16 students in the whole group. Among them, 8 students are willing to go to a's, 6 students like to go to B's, and two students think it's OK to go to both. The survey results show that the sales mode of a commercial building is more attractive, but is it true? In practical problems, a commercial building pays more attention to the sales turnover and

Conversion of physical units
65mm=( )m
5 * 10, NM = () cm = () M = () km
06 * 10, KM = () DM = () um = () nm
6min=( )s=( )h

65mm = (0.065) M1.5 * 10 to the fifth power nm = (0.015) cm = (1.5 * 10 ^ (- 4)) M = (1.5 * 10 ^ (- 7)) km 4.06 * 10 to the negative fifth power km = (0.406) DM = (4.06 * 10 ^ 4) um = (4.06 * 10 ^ 7) nm 6min = (360) s = (0.1) H

4a^2+12ab+9b^2-25

This topic mainly investigates the comprehensive application of complete square formula and square difference formula!
4a^2+12ab+9b^2-25
=(2a+3b)^2-5^2
=(2a+3b+5)(2a+3b-5)

R1r2 is incorporated into the circuit, and R1 is greater than R2, R2 = 10 Ω. The electric power consumed by resistor R1 is 0.6 W, and the current in the trunk circuit is 0.5 A. what is the resistance of R1? How much is the current

According to the equal parallel voltage, the current in the trunk is the sum of branch currents
(0.5-0.6 / R1 under radical) = 0.6 * R1 under radical
Find R1

When an object moves in a straight line with uniform acceleration, the initial velocity is 0.5m/s, and the displacement in the 7th second is 4m more than that in the 5th second
What is the displacement of the object in 5S? Why is it 27.5m instead of 25m?

Suppose the acceleration is a, then the velocity after 1s is 0.5 + A, the velocity after 4S is 0.5 + 3a, the initial velocity within 5S is 0.5 + 4a, the final velocity is 0.5 + 5a, the initial velocity within 7S is 0.5 + 6a, the final velocity is 0.5 + 7a, the initial velocity within 7S is 0.5 + 6a, the final velocity is 0.5 + 7a, the initial velocity within 5S is 0.5 + 4a, the final velocity is 0.5 + 7a, so 1 / 2 * 1s * (0.5 + 6a)

How to determine the sign of complete square formula
How do you know for sure

For example
（a+b）²
=（a+b）×（a+b）
=a²+ab+ba+b²
=a²+2ab+b²
It can be seen that because it is a + B, the result is + 2Ab
Similarly (a-b) & # 178; because it is A-B, the result is - 2Ab
（a-b）²
=（a-b）×（a-b）
=a²-ab-ba+b²
=a²-2ab+b²
It's really easy to remember
This mathematics is still very shallow, you must write it down, otherwise you will not study hard in the future!
If you have any questions, please ask. Thank you