Mark M. answered 04/02/15
Tutor
4.9
(952)
Retired Math prof with teaching and tutoring experience in trig.
tan(x + π) = (tanx + tanπ)/[1-(tanx)(tanπ)] = tanx, since tanπ=0
cos(x + π/2)=cosx cos(π/2)-sinxsin(π/2)=-sinx, since
cos(π/2) = 0 and sin(π/2) = 1
So, the original equation simplifies to tanx + sinx = 0
sinx/cosx + sinx = 0
(sinx + cosxsinx)/cosx = 0
sinx + cosxsinx = 0
sinx(1 + cosx) = 0
sinx = 0 or cosx = -1 x = 0, π
Mark M.
tutor
(sinx + cosxsinx)/cosx = 0
The only way for a quotient to be 0 is for the numerator to be 0.
So, sinx + cosxsinx = 0
Report
04/03/15
Tyler L.
04/02/15