Homogeneous formula of sine and cosine means that the exponents of cosine function are the same in the expression.
For example: tanx=2, find: (sinx+3cosx)/(sinx-4cosx).
The above formula is the homogeneous formula of sinx and cosx, which can be found by transforming it into tanx.
If the numerator and denominator are divided by cosx, then the original formula =(tanx+3)/(tanx-4)=-5/2.
It is a common skill to change the homogeneous expressions of sinα and cosα into tgx expressions, which should be mastered skillfully.