Help me with this determinants question?

Prove that the value of the following determinant is ZERO:

|sin^2(23)° sin^2(67)° cos180°|
|-sin^2(67) -sin^2(23)° cos^2(180)°|
|cos(180)° sin^2(23)° sin^2(67)°|

I have been trying for hours but keep getting the wrong answer?
2 answers 2