which equation is trigonometric identity

[tex]\boxed{\sin^2x+\cos^2x=1}[/tex]
[tex]\sin^2x=\cos^2x+1\ WRONG\\\sin^2x=1-\cos^2x\ CORRECT\\---------------------------\\\tan x=\dfrac{\cos x}{\sin x}\ WRONG\\\tan x=\dfrac{\sin x}{\cos x}\ CORRECT\\-------------------------\\(\sin x+\cos x)^2=1\ WRONG\\\sin^2x+\cos^2x=1\ CORRECT[/tex]