Slope formula of two straight lines Given the angle a between two straight lines and the slope of a straight line, is there a formula for calculating the slope of another straight line?

Slope formula of two straight lines Given the angle a between two straight lines and the slope of a straight line, is there a formula for calculating the slope of another straight line?

There's Tan @ = (D-K) / 2 * D * k @ is the angle, D is the slope of one line, K is the slope of the other line, and * is the total absolute value after multiplying by the equal sign. I can't get this sign on my mobile phone. The final absolute value of the two slopes minus two times the slope of the last line is because the angle is not negative

The formula of the slope of a straight line
I want a formula~

Let two points be (x1, Y1)
(x2,y2)
k=(y2-y1)/(x2-x1)

Help me summarize all the formulas for finding the slope of a straight line,

There are two ways to find the slope of a straight line
(1) According to the relationship between the inclination angle and the slope of the line, that is, the slope of the line is equal to the tangent of the inclination angle of the line
(2) The slope of a straight line is equal to the difference between the ordinates of two points divided by the difference between the abscissa