Answer:
nπ/2
Explanation:
y = ln(tan(x)²)
ln(x) is undefined when x ≤ 0 or undefined. Since tan(x)² is squared, it's never negative. So we need to find where it's 0 or undefined.
tan(x) is 0 at x = πn.
tan(x) is undefined at x = π/2 + πn.
So tan(x) is 0 or undefined at x = nπ/2.