y = (sin x) / (1 + tan x)

3 answers

Is there a question here?
Sorry
y'=
just use the quotient rule. If
y = u/v
y' = (vu'-uv')/v^2

y' = [(1+tanx)(cosx) - (sinx)(sec^2 x)]/(1+tanx)^2
= ((cosx - (sinx)(tan^2 x))/(1+tanx)^2