Mathematics for IGCSE & O level - Coordinate Geometry (Section 3 - No. 6)
If the equation of line 1 is y= -x+3 and the equation of line 2 is x+y=5, what is true?
Line 1 has a negative slope.
Line 2 has a negative slope.
The lines are parallel.
The lines are perpendicular.
설명
The slope for line 1 is -1, and line 2's slope is also -1 (after rearranging into slope-intercept form). Then these are parallel and perpendicular because the two slopes' multiplication = 1.