SP #7: Unit Q Concept 2 (Finding All Trig Functions When Given One Trig Function and Quadrant)

Solving with SOH CAH TOA:

1.

2.Solving with Identities:

When finding actual trig functions, we can use two methods: SOH-CAH-TOA or Identities! As you can see from the first photo, we refer back to our Unit circle and can use the Pythagorean Theorem to get our missing side with the two we already have. In our case, we go to the sin where we know the fraction is y/r. If we place it into the formula, our "x" will be one! The second method is through identities! When using our identities, we are always given two trigs which cuts down a portion of our work! With these two, we first figure out in which quadrant the answers will be either negative or positive in (please refer to the second picture). After that is when we either substitute or solve for the proper trig that we are looking for.