If Tan A/ Tan B = n and Sin A / Sin B = m. Then show that cos A =√(mn) ^2+m^2-n^2-1/n^4-1

If Tan A/ Tan B = n and Sin A / Sin B = m. Then show that cos A =√(m

1.	If Tan A/ Tan B = n and Sin A / Sin B = m. Then show that cos A =√(mn) ^2+m^2-n^2-1/n^4-1
Answer» Okk