BQ#2: Unit T Concept Intro

A)   When is comes down to sine and cosine, their periods are are 2pi and it's like that due to their similarity to the Unit Circle.

Sine in the Unit circle is positive in the first and second quadrant and negative in the third and fourth quadrant. If we start from zero and do one complete rotation to get it to be positive again, then then it was a 360 degree or 2pi rotation. So when we stretch Unit Circle into a line, the cyclical will be stretched out too because the first two quadrants will be above the x-axis and the last two will be below the x-axis. 

The same thing goes for cosine since quadrant I and IV are positive and quadrant II and III are negative. We need to start at 0 degrees and as we move around in the Unit Circle well reach the positive when we get to 360 degrees. When it reaches 360 degrees the it made one complete rotation. If the stretch out the Unit Circle to a straight line for cosine then we will start above the x-axis since quad. I is positive and for quads II and III it will be below the x-axis. As we approach quad IV to make a cyclical then it go back up above the x-axis.

For tangent it's different because it's only half the trip to get a cyclical. Quadrants I is positive and quadrant II is a negative so we already have our cyclical. On the Unit Circle, it will start at 0 degrees and when we reach a positive again it will be at 180 degrees and the radian value is pi.

B)    Sine and cosine only have an amplitude of 1 because they have a restriction of 1 and -1. If we use any number and use it in their ratio, it will not work except those numbers less than 1. We only use the 1 in the Unit Circle then sine and cosine will work because it is in their restriction,  if it wasn't then it will be undefined and will not work.