Sine graph question for math

[AgaBoogaBoo]

One porblem says this: Write an equation for the graph of a sine curve that has a period of 3pi and an amplitude of 4. I know it starts out with y = 4sin(x) with something inside the brackets multiplying the x. If I put a .5 there, the period is 4, if I put a 1 in there, it's 2. So logically, the average of those two should be 3 and .75. When I put this into the calculator, it doesn't work. Why doesn't this work?

 

[Martin]

peroid of sinBx is 2pi/B

so you want 2pi/B = 3pi >> B = 2/3

 

[Soccer55]

Use the formula for period in order to find out what your frequency should be. period = 2*pi/b where b is found in the general form of the sine equation y = a sin(bx-c) + d. So just figure out what b should be and sub it in along with what you already have for the amplitude.

-Tom

 

[AgaBoogaBoo]

Originally posted by: Soccer55
Use the formula for period in order to find out what your frequency should be. period = 2*pi/b where b is found in the general form of the sine equation y = a sin(bx-c) + d. So just figure out what b should be and sub it in along with what you already have for the amplitude.

-Tom

Thanks!!!

 

[Soccer55]

Originally posted by: AgaBooga

Originally posted by: Soccer55
Use the formula for period in order to find out what your frequency should be. period = 2*pi/b where b is found in the general form of the sine equation y = a sin(bx-c) + d. So just figure out what b should be and sub it in along with what you already have for the amplitude.

-Tom

Thanks!!!

No problem.

-Tom

 

[BaboonGuy]

man that was easy