How To Prove Perpendicular?

Answer 1

Perpendicular Numerical criteria

In terms of slopes
In a Cartesian coordinate system, two straight lines L and M may be described by equations

L:y = ax + b,
M:y = cx + d,
as long as neither is vertical. Then a and c are the slopes of the two lines. The lines L and M are perpendicular if and only if the product of their slopes is -1, or if ac = − 1.

Answer 2

prove that m of the angle is 90*
if you want to prove two lines are perpendicular prove the product of their slopes is -1

Answer 3

The product of the gradients of the two lines must = -1.

Hope this helps=)

Answer 4

if u want to prove it for two lines
product of their slope is -1

Answer 5

if tou are talking vectors dot product should be zero. Question is incomplete.

in co-ordinate geometry product of slopes -1

Answer 6

(Assuming you mean two-space, not 3-space.)

Depends on what you were given:
two equations of lines, slope and one point or two points on each line

The perpendicularity test is: slope_1 * slope_2 = -1

So if you were given two points for each line (P1,P2 for L1 and Q1,Q2 for L2),
the test would be:
(py2-py1)/(px2-px1) * (qy2-qy1)/(qx2-qx1) = -1

Answer 7

Use a pair of compasses.

Answer 8

Very informative question !