Precal Blog

We began class today on the packet with the final example question:

The graph of points from (U,V). U= -8 and V= 5, comprise in the formation of a 90 degree angle. From this we can use Pythagorean theorem a^2+b^2=c^2. (the reference angle is counterclockwise and is positive but is not needed for this). This answer we found  from the terminal position’s length of square root of 8.  Looking back and remembering that sine= opposite / hypotenuse and cosine = adjacent/ hypotenuse and later finding the sine and cosine to the terminal position. Sine theta = 5/square root:89 and cosine theta = -8/square root:89. Now since the terminal angle ends in the second quadrant coordinate plane, cosine is going to be (-) and sine is going to be positive (+).Towards the end of class we looked at graphs of the sine and cosine functions (graphs A and B). Graph A is y= cos(X) and Graph B is y= sin(X). In comparing the sinusoids one can see the periodic function as cos(X) repeats itself through a cycle that sin(X) is inversly related to.

The next scribe is Jack K.