Distinct solutions

sin5@cos3@=sin9@cos7@
=> sin8@ + sin2@ = sin16@ + sin2@
=> sin8@ = sin16@

or 16@ = n∩ + (-1)ⁿ8@

seeing the various cases,
8@ = 2m∩, or 24@ = (2k+1)∩
@ = 2m∩/8 = 0, ∩/4, ∩/2 OR @ = ∩/24, ∩/8, 5∩/24, 7∩/24, 9∩/24, 11∩/24

So 9 solutions

Answer is 9 solutions

yeah 9 solutions ... din see that the interval was ∩/2 included...