I do not see why I got two different equations for my answer
A weight attached to the end of along spring is bounicng up and down. As it bounces, its distance from the floor varies sinusoidally with time. You start a stopwatch. When the stopwatch reads 0.3 s, the weight first reaches a height point 60 cm above the floor. THe next low point, 40 cm above the floor, occurs at 1.8 s.
Write an equation expressing distance from the floor in terms of the number of seconds the stopwatch reads.
I got two answers and don't see why
50 + 10sin 1.5^-1(x+.45)pi
50 + -10 sin -1.5^-1 (x - 2.55)pi
1 answer
They are different by 3 PI. Think about the sine function with a difference of 3PI, it changes sign. So, it is right, as if you add 3 pi, the sign changes, they are the SAME answer.