A harmonic wave on a string moves along the x-axis according to:

î(x,t) = 5.0 (cm) sin[ (2.5m-1) x - (63s-1) t ]

At x = 1.0 m when t = 2.2 s the speed of the oscillations on the string is closest to ...

25.2 m/s
4.55 m/s
3.15 m/s
2.27 m/s
1.67 m/s

2 answers

its definitely not 25.2 or 3.15
then what is is? how do you solve this?? im so confused :(