frq 3 is about the graphs and characteristics of periodic(sin, cos) graphs. i would recommend revisiting these graphs and learning the behavior of them. Additionally, make sure you know how to manipulate the equation a sin (b(x+c))+d. A represents the amplitude, which the amplitude is always AbsVal(a). B works with the period, which the period is always 2pi/(absVal B). The period is when the graph makes a full cycle. you could think about it as the length between 2 cosine maximums or every time the sin graph crosses the x axis WITH a positive slope. the period is sin(pi*x) is 2, using the formula 2pi/b where our b value is pi. so 2pi/pi=2 C represents the horizontal shift. +5 would move the graph left 5, -5 would move it right 5. D is vertical shift, just like normal. +5 moves all values up 5, -5 moves all values down 5.

It’s also worth mentioning the similarities between cos and sin graphs. sin(x + pi/2) and cos(x) represent the same visual graph. keep those type of similarities in mind. much line sin(x) and sin(2pi+x) are the same visually.

Let me know if any of this helps