Trig functions

[Jess]

I absolutely hate trig functions

can someone help me?

1. http://homework.math.pitt.edu/cgi-bin/plot.png?file=jzc22_pitt_1347224960_20442982_plot.data

2. http://homework.math.pitt.edu/cgi-bin/plot.png?file=jzc22_pitt_1347224945_18587215_plot.data

3. http://homework.math.pitt.edu/cgi-bin/plot.png?file=jzc22_pitt_1347224871_21538991_plot.data

I need to figure out the amplitude, period, and equation of these three graphs. I seem to have more trouble with the equation than the amplitudes and periods. I think I can figure out the amplitudes, but I don't know if I'm right or not

[Gigablue]

The first equation is y=10cos(2x), the second is y=4sin(9x/10)+2, and the third is y=3cos((π/2)x)+6. You should be able to find the amplitude and periods using the equations or just by looking at the graphs, but let me know if you need help with those as well.

[Jess]

thanks! I'll let you know if I need more help :S

[Gigablue]

The period of the first one is π. The second one has a period of 20π/9. The third has period 4.