Student Problem Unit R Concept 1

Using the difference Formula

using the Sum Formula

• What is this problem about?

This picture goes over a problem from Unit R concept 1, dealing with finding the exact values of sums or differences. This is also an example of finding exact values for angles that aren't on the unit circle, but rather now we are able to use our knowledge from the angles given on the unit circle to solve for other angles that are not put on the circle. By using the sum and difference identities we are able to solve for these non apparent unit circle angles and use the other angles given on the unit circle to help figure out the exact values. We basically are trying to figure out which angles on the unit circle can add or subtract to the angle in which we are solving for, and in this concept we can see that there are various ways in which we can go about solving these problems. 

• What does the viewer need to pay special attention to in order to do the problem correctly?

In order to solve the problem correctly the viewer needs to make sure that he/she is very familiar with the unit circle. Due to the knowledge we take away from the unit circle it is imperative that we know the ordered pairs for the magic five and are familiar with identifying sin, cos, and tangent using the ordered pair that corresponds with the angles used. It is also important that we are all familiar with SOHCAHTOA and what that stands for in order to identify the trig functions for each of the angles used. Also, very important is that we need to focus on memorizing the sum and difference formulas so that we don't have to keep referring back to the notes. The last crucial thing one must do to solve correctly is checking your answers and also making sure that it is all plugged in correctly.