Aaah,
thank you Mr. Ebberts, I think I see,
While the sine wave is above the x Axis it’s gotta positive value thus, the expression gives opacity 100% (for any positive including Zero), then when the sine wave goes to a negative value the expression gives it an opacity of 0%.
And dividing Pi by the time you want it to take to flash on and off, you constrain the Freq of completing a full circle to take F (in this case) seconds?
Is my understanding correct?
Thanks,
Derrick