Question

已知P1(-1,a),P2(3,6)且p1p2的斜率k=2,|p1p2|=?求详解

Answer 1

k=2

(6-a)/(3+1) =2

6-a=8

a=-2

|P1P2|^2 = (3+1)^2 + (6+2)^2=16+64=80

P1P2=4√5