8-2 Graphing Sine and Cosine Curves

Graphing Sine and Cosine Curves

Steps to graphing a trig function:

Before you begin your steps in graphing a trig function, you must first identify the graph as sine or cosine. Sine will start at the origin, going up or down, and cosine will start above, going down, or below it, going up.

1. You must first identify if there's a negative, and which way it will start.
   
   



2. Find the period: 2pi/B





3. Find the amplitude: y=A sinBx y=A cosBx *Amplitude cannot be a negative. *A negative infront of sin or cos flips the curve.





4. Write your 5 imp. points: 0, pi/2, pi, 3pi/2, 2pi





5. Divide every point by "B".





6. If there's any number that's added or subtracted in parenthesis, do the opposite for all 5 points.





7. Sketch your graph.





8. Shift points up or down if anything is added or subracted in parenthesis. *The shift goes in the same direction.

Example : Graph y=3 sin2x

1. the graph is sin starting at the origin, going up





2. period= 2pi/B: 2pi/2= pi





3. amplitude= 3





4. /5./6. 0 0/2= 0

pi/2 (pi/2)/2= pi/4

pi pi/2= pi/2

3pi/2 (3pi/2)/2= 3pi/4

2pi 2pi/2= pi

7.)

--Jordan Duhon:)