In which interval does the first question 2 x+x+ 1 = 0 have a solution? Draw an image with y = 2 x and an image with y=-x- 1 on paper. Obviously, their intersection is in the interval (-2,-1), so 2 x+x+65438.

Second, since the midpoint of AB is (3, 1), assuming the slope exists, the equation of straight line AB is y- 1=k(x-3), and the general formula is

y- 1-k(x-3)=0

Because the line whose center connects the midpoint of chord AB will be perpendicular to AB, the inverse of the slope of the line whose center connects the midpoint of chord AB will be the slope of straight line AB.

K=- 1 is obtained from the center of the circle (2,0) and the midpoint of chord AB (3, 1).

So the equation of straight line AB is y+x+2=0.

The third question The third question can be based on the idea of the second question. The line between the center of the circle and point p is multiplied by L 1, and their slopes are equal to-1.

You can set the center of the circle as (a, b) and substitute it into L2 to get the relationship between A and B.

Then find the slope.

Calculated by multiplying the slope by-1.

I won't write detailed answers.

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