I know the title is a bit, undiscripive...but I did not know what to call this.
makes little since to me.
(I know waves in physics, not algebra)
I know that the two waves are out of phase and cause destructive interference (wave cancellation)
But, the two waves should cancel at equilibrium (where the cos & sin waves meet ~the nods~). High presser+low presser=medium pressure (equilibrium)
The peak for both and is at one, and the trough for both is at 0.
So why not :