Question

Find the exact values of the following.

cos 270 degrees = 90 degrees, value = 0.

Sin 180 degrees = 180-90 = 90 = 1, but its supposed to be zero, don't know how to get that:\

Confused with tan 240 degrees as well.

Answer 1

for the first two, like I told you in the last post, look at the graphs

for tan 240°
1. where is the angle ? in III , so the answer is -
2. how far to the x-axis? 60°

so tan240° = -tan60° = √3/1 , (from the 30-60- 90 triangle ratio)

always check with your calculator