Answer:
the first option 0, pi
Step-by-step explanation:
remember, tan(x) = sin(x)/cos(x)
therefore, tan(x) = 9, when sin(x) = 0.
and that is the case at x = 0, and at x = pi.
and when sin(x) = 0, we also get sin(x)cos(x) = 0.
the alternative would be to bring cos(x) to 0.
but, remember the definition of tan(x). this would give us 1/0, and that is undefined and not 0.
so, the only possible solution is for sin(x) = 0 with the above solution.
