1. The problem statement, all variables and given/known data "A sinusoidal wave is propagating along a stretched stringas a function of time is graphed in the figure (attached) for particles at x = 0 and x =0.0900m. a) what is the period of the wave ( my ans = 0.04 sec b) what is the amplitude of the wave ( my ans = 4mm) c)you are told that the 2 points x=0 and x=0.0900m are within one wavelength of each other. If the wave is moving in the +x direction, determine the wavelenght and the wave speed." 2. Relevant equations y(x ,t) = A cos(2pi ( x/lambda - t/T)) ie the mathematical representation of a wave 3. The attempt at a solution I have already posted this Q previously, but fear that how I posted it made it seem unsolvable, this is what I did again: 0.75 = cos (2pi (0.09/lambda - 0 )) where I get lambda, and thus wavelength to equal 0.78...... which isnt correct since the answer is something like 0.14m any pointers on how to solve would be great!!