(4-1) 

① (a) below is just the graph of y = sin(x)  (where x is an angle in radians). Note that the wavelength equals 2π radians.  The other three are all transformations of this curve. See if you can figure out the equations for each of these.

②  Taking on board the corrections you have applied to generate the correct equations in these examples, see if you can write a general equation for a sinusoidal curve (ie a graph of this general shape), in terms of A and λ.