If lines y=mx+b and x=y+bm intersect at a degrees angle (where a<90 ), what is the value of angle a ?
We can find the angle of intersection b/w any 2 lines if we knw the values of their individual slopes.
For y = x + bm, slope is 1; for y = mx + b, slope is "m"
(1) Tan (a) = (m - 1)/(1 + 1*m); tan(a) < 90 if its value is +ve;since m-1>0, no need to add/subtract from 180.
Since statement 2 gives m=2, it is sufficient.
(2) Test y=x+1, y=2x+2 and y=3x+3
with "y=x - 1, y=x-4, and y=x-9
y=x+1 and y=x gives 0 degrees
y=2x+2 and y=x-4 gives a diffrent value...INSUFF
KUDOS me if you feel my contribution has helped you.