The graph of the function y = - 3x + 12 is drawn, and the solution set of inequality - 3x + 12 > 0 is obtained by using the image. (2) the solution set of inequality - 3x + 12 ≤ 0 is obtained

The graph of the function y = - 3x + 12 is drawn, and the solution set of inequality - 3x + 12 > 0 is obtained by using the image. (2) the solution set of inequality - 3x + 12 ≤ 0 is obtained

The image of the function y = - 3x + 12 is a straight line passing through points (0,12) and (4,0). As shown in Figure 1, the X axis divides the line into three parts: y is greater than 0, equal to 0 and less than 0. The corresponding value range of X corresponds to the three parts of x < 4, x = 4 and x > 4

Solving inequality 2 / 2 X-5 + 1 > x-3

Favor in the sun:
(x-5)/2+1>x-3
(x-5)/2>x-4
x-5>2(x-4)
x-5>2x-8
x-2x>-8+5
-x>-3
X

What is the solution set of the root sign 2 of the inequality cosx > 2?

cosx > √2/2
2K π - π / 4 < x < 2K π + π / 4, where k ∈ Z

What is the solution set of the inequality cosx > root 2?

Then, Cos2 π

The solution set of inequality radical 2 / 2 ≤ cosx ≤ 1 / 2 is

-Radical 2 / 2 ≤ cos x ≤ 1 / 2
2K π + π / 3 ≤ x ≤ 2K π + 3 π / 4,2k π - 3 π / 4 ≤ x ≤ 2K π - π / 3, where k ∈ Z
Namely:
x∈【2kπ-3π/4,2kπ-π/3】,【2kπ+π/3 ,2kπ+3π/4】k∈Z

Is the solution set of inequality 1 / 2 ≤ cosx ≤ radical 3 / 2?

[2kπ-(π/3),2kπ-(π/6)]∪[2kπ+(π/6),2kπ+(π/3)]

If x ∈ [0,2 π), what is the solution set of inequality SiNx ≤ cosx?

sinx-cosx≤0
√2sin(x-π/4)≤0
-π/4≤x-π/4<7π/4
So - π / 4 ≤ X - π / 4 ≤ 0, π ≤ X - π / 4 < 7 π / 4
So 0 ≤ x ≤ π / 4,5 π / 4 ≤ x < 2 π

Given the functions SiNx and cosx, X ∈ (0360), find the solution set of inequality SiNx ≤ cosx

Understand the characteristics of SiNx and cosx
In the upper left part of the line y = x, SiNx > cosx
The lower right part of the line y = x is SiNx

Solving inequality SiNx > cosx How many solutions do you have?

Using the combination of number and shape
1. Draw a circle in the coordinate system, the radius of the circle is unit 1, and find the set of SiNx > cosx in the circle
2. Draw the images with function image method and find the set of SiNx > cosx

Solve the inequality group cosx ≤√ 3 / 2, cosx > SiNx

Consider 0 ≤ x first