Consider the following standing wave, (all units are SI)

z=0.2sin(0.4y)cos(350t)

(a) what is the wavelength?

(b) what is the angular frequency ω in radians/sec?

(c) what is the frequency (f) in Hz?

(d) The values of y where the displacement is always zero, are of the form y=a+bn, where n=0,±1,±2,3, etc.

What is b?

(e) The values of t where the displacement at all values of y equals to zero are of the form : t=c+dn, where n=0,±1,±2,3, etc.

What is c?
What is d?