Answer: c perpendicular
Step-by-step explanation:
y=x+12 y=mx+b m=1 slope 1
Y=-x+1 m=-1 slope -1
slopes are perpendicular obviously, or
(1,y(1))-(0,y(0)) = (1,13)-(0,12) = (1,1)
(1,Y(1))-(0,Y(0)) = (1,0)-(0,1) = (1,-1)
(1,-1) dot (1,1) = 1×1+1×-1 = 0 therefore perpendicular.
Two vectors are perpendicular if and only if their dot (inner) product is zero, or the projection of one onto the other is zero, or if the cosine of the angle between them is zero.
