In a circle with center O, the length of radius OB is 5. If the length of chord CD is 8, and if line CD perpendicular to line OB, then sin angle OCD =

Start by drawing it! Note that OC = 5 and OD = 5 because both of those are also radii. Note also that because chord CD is perpendicular to OB, it’s bisected by OB. In other words, it’s split into 2 segments each measuring 4.   Things are really coming together! Because we know our Pythagorean (more…)

In the xy-plane what is the slope of the line that passes through the origin and makes a 42° angle with the positive x-axis? A. 0.67 B. 0.74 C. 0.90 D. 1.11

Trigonometry does the trick here. Below is that line making a 42° angle with the positive x-axis. I’ve also drawn a dotted segment to make myself a neat little right triangle. Remember that slope is rise over run—how high the line climbs divided by how far it travels right. In this case, the dotted segment (more…)