Question

is the line through points p(-8,-10) and q(-5, -12) perpendicular to the lines through points r(9, -6) and s(17, -5)? Explain.

Answer 1

Answer: Consider this option:

1. rule: if the scalar product PQ*RS=0, then PQ⊥RS.

2. PQ=(3;-2), RS=(8;1).

3. The scalar product of PQ*RS=3*8-1*2=22≠0. The line included PQ is not perpendicular to the line included RS.

Explanation: