I need someone to walk me throught this math problem for trigonometry. I know the answer is A.?

Question

One of the graphs below is that of y = A sin 0 for 0 between 0 and 6.28 radias, where A is a constant. Which one?

You can see the graphs at the link below, it is questions number 6 in the Trigonometry placement test questions.

Answer 1

y = a sin bx is the general form for a sine curve.

a = amplitude (how high/low it goes)

b = frequency (how many cycles I have in an interval, in this case 0 and 6.28)

period = 2pi/b

In this case the period is 2pi or roughly 6.28. That's how long it takes for ONE CYCLE TO COMPLETE.

In your equation  y = A sin 0 (theta). Again, the frequency (number in front of theta) is ONE which means I'll have one cycle between 0 and 6.28.

that pretty much narrows it down to choices A and B. you should also know how a sine curve looks. It starts at the origin.