>>10976527Undefined .
But if you focus on the graph at point when sin wave go to 1 and cos go to 0 you can mean that it is a point of singularity. Just like 1 is a point of singularity for Riemman Zeta function. It's not undefined we just have to define some symbol to it and describe it's interaction with other thing. Like blackhole suck in everything but only when you go inside you will ever find out what actually happens there.
