Question

cos(a+b)/(cos(a)cos(b)=1-tan(a) tan(b) verify the identity step by step

Answer 1

Try replacing these in your equation:
\(\cos(a+b)=\cos (a)\cos (b)-\sin (a)\sin (b )\)
\(\tan( a) =\dfrac{\sin(a)}{\cos(a)}\), and do the same for \(\tan(b)\)

You should be able to seequickly how both sides are equal when you do this

Answer 2

sounds good. Thank you!

Answer 3

=] your welcome