Uploaded October 2024 | Updated September 2026, 2 hours ago
In this video we solve some basic trig equations that have sine and cosine on both sides of the equal sign. The method we use is to manipulate one side until you either have sine on both sides or cosine on both sides, then we just equate the arguments. There are a lot of skills we have to use to be successful here:
1) Finding coterminal angles
2) Cofunction identities
3) ASTC to find signs and reference angles in different quadrants
4) The Unit Circle and what it tells us.
Time stamps:
[00:17] Prerequisite skills
[02:18] Example 1: sin(x) = sin(573) (degrees)
[04:59] Example 2: cos(x) = cos(98) (degrees)
[06:24] Example 3: sin(x) = cos(230) (degrees)
In this video we solve some basic trig equations that have sine and cosine on both sides of the equal sign. The method we use is to manipulate one side until you either have sine on both sides or cosine on both sides, then we just equate the arguments. There are a lot of skills we have to use to be successful here:
1) Finding coterminal angles
2) Cofunction identities
3) ASTC to find signs and reference angles in different quadrants
4) The Unit Circle and what it tells us.
Time stamps:
[00:17] Prerequisite skills
[02:18] Example 1: sin(x) = sin(573) (degrees)
[04:59] Example 2: cos(x) = cos(98) (degrees)
[06:24] Example 3: sin(x) = cos(230) (degrees)
