Home  18.013A  Chapter 2  Section 2.2 


Derive the relations between these functions by using similar triangles.
Solution:
By similar triangles, the ratio of BD to BO, sin to 1 is the same as the ratio of CB to OC, tan to sec, and of OB to AO (1 to csc), and of CO to AC (sec to (tan + cot)), and of CD to BC ((sec cos) to tan), and of OE to BO (sin to 1)
This tells us
so that on taking complements we have as well,
We also get
and the complementary result
