1) show that A (1,-2), B(4,4) and C (5,6) are collinear. 2) Find b given that A (-6,2) B (b,0) and...

1) show that A (1,-2), B(4,4) and C (5,6) are collinear.

2) Find b given that A (-6,2) B (b,0) and C (3,-4) are collinear.

3)Find the equation of the:
a) tangent to the circle with center (-1,2) at the point (3,1)
b) perpendicular bisector bisector of (AB) for A (2,6) and B(5,-2).

4) a) For P( -1,2,3) and Q (1,-2,-3), find: 

i) the distance of PQ ii) the midpoint of (PQ) 

b) Find K if P is ( 1,3,-1), Q is (2,1,K), and PQ=√30