Answer:
There is no “formula” and the sooner you stop believing that math is a collection of formulas the sooner you can start learning it.
“Y sinx”, as written, is meaningless. You probably meant y = sin(x). Learning the proper grammar and syntax for writing mathematical expressions is necessary to make any progress in the subject.
Finally, the value of y = sin(x) is the y-coordinate of a point on the unit circle at position angle x. the zeros of y = sin(x) are x = k*pi, where k is any integer, because at any of those position angles the y-coordinate will be 0. This is not a “formula”, just a compact way to indicate an infinite number of zeros. The note that k is any integer is generally assumed, but to be clear and precise it should be included as part of the answer.
Solutions to trig equations are often restricted to the domain [0, 2pi), which is once around the unit circle without repetition of any point. On this domain, the zeros are 0 and p