TRIG
posted by rossi on .
what is another form of: sin (A+B) sin (AB)/ cos^2 A cos^2 B
a) cos^2 A  cos^2 B
b) tan^2 A  tan^2 B
c) tan^2 A  tan^2 B
d) sin^2 A  sin^2 B
please show the steps you take to get to the answer! thank you

sin (a+b) = sin a cos b + cos a sin b
sin (ab) = sin a cos b  cos a sin b
product
sin^2 a cos^2 b  cos^2 a sin^2 b
now divide by cos^2 a cos^2 b
sin^2 a/cos^2a  sin^2 b/ cos^2 b
= tan^2 a  tan^2 b