Circles With and Without Coordinates #3

Question

In the diagram,  is a diameter of circle O. If the slope of  is , what is the slope of  ?

A. 

B. 

C. 

2

D. 

-2

E. 

-4

Answer 1

angle B is 90 ( half of the half-circle)

so these 2 lines are perpendicular and therefore their slopes are negative-reciprocal

so if one is -1/2 - another is +2

Sarah, if you want a geometry lesson - please let me know