# trigonometric curve

• May 18th 2008, 08:05 AM
MrOats
trigonometric curve
Please check to see if I did this right? I need correct answers soon! Thank you very much.

"The Second Question" Sin Wave Question:
"A student attaches one end of a rope to a wall at a fixed point 3 feet above the ground, as shown in the accompanying diagram, and moves the other end of the rope up and down, producing a wave described by the equation y = a sin bx + c. The range of the rope’s height above the ground is between 1 and 5 feet. The period of the wave is [4(pie symbol)]. Write the equation that represents this wave."

http://farm4.static.flickr.com/3150/...9b1c5b2a67.jpg
I got Amplitude = 4, Period = [2(pie)/b], Frequency = 2/4

And for the equation: y= 4 Sin (2/4(x)+4)

...I really am unsure about this one. Someone please clarify for me? I need to get "solid" in my head what the amplitude, frequency, period, and range are...And solid, a=, b=, c=...answers.

Please help me demystify this sin wave question! Thank you.
• May 18th 2008, 08:20 AM
galactus
Was your first one:

$\frac{2cos{\theta}}{sin2{\theta}}$?.

If so, it is equal to $csc{\theta}$

Because $\frac{2cos{\theta}}{2sin{\theta}cos{\theta}}=\frac {1}{sin{\theta}}=csc{\theta}$