When k is equal to something, there is no intersection between the inverse proportion function y = 1 / X and the straight line y = kx-1, and the reason is given Of course, the correct answer is K

In the past
1/X=KX-1
Go to the denominator and make it less than 0
If there is an intersection point, then the coordinates of that point satisfy two equations at the same time, that is, the two equations have a common solution, that is, 1 / x = kx-1 can be solved
If there is no intersection point, it will be the opposite. If 1 / x = kx-1, there will be no solution, that is, the delta value is less than 0

If the positive integer solution of inequality 3x-k less than or equal to 0 on X is 1.2.3, then what is the value range of K? There is another problem in the supplementary explanation
Given x 2 + X + 1 = 0, find the value of x 3 + 2x 2 + 2x - 3

1. From the solution of 3x-k ≤ 0, X ≤ K / 3 is obtained
Because the positive integer solution of inequality has 1,2,3
So 3 ≤ K / 3 < 4
So 9 ≤ K < 12
2. X2 + X + 1 = 0, both sides of the equation are multiplied by X at the same time
X3+X2+X=0
So X3 + 2x2 + 2x-3 = (X3 + x2 + x) + (x2 + X + 1) - 4 = 0 + 0-4 = - 4

Given the function f (x) = (12x-1 + 12) SiNx & nbsp; (- π 2 < x < π 2 and X ≠ 0) (1) judge the parity of F (x); (2) prove that f (x) > 0

(1) ∵ f (- x) = (12-x-1 + 12) sin (- x) = - (112x-1 + 12) SiN x = - (2x1-2x + 12) SiN x = (2x2x-1-12) SiN x = [(1 + 12x-1) - 12] SiN x = (12x-1 + 12) SiN x = f (x), f (x) is even function. (2) when 0 ＜ x ＜ π 2, 2x ＞ 1, & nbsp; & nbsp; 2x-1 ＞ 0 & nbsp; & nbsp

When k is equal to something, there is no intersection between the inverse proportion function y = 1 / X and the straight line y = kx-1, and the reason is given Of course, the correct answer is K