Line AB and Line BC form a right angle at their point of intersection, B.

Question

Line AB & BC form a right angle at their point of intersection B.

If the coordinates of A and B are (14, -1) and (2, 1), respectively, the y-intercept of line AB is _ and the equation of line BC is y=_x +_.

If the y-coordinate of point C is 13, its x-coordinate is_.

Answer 1

The slope of AB is (1-(-1))/(2-14)=-2/12=-1/6; y-1=-(1/6)(x-2)=-x/6+1/3; y=(4/3)-x/6, so the y intercept is 4/3.

The slope of BC is 6 because AB and BC are perpendicular, so the product of the slopes=-1.

The equation of BC is y-1=6(x-2); y=6x-11. When y=13, 13=6x-11, 6x=24, x=4.