Which equation can be used to prove 1 + tan2(x) = sec2(x)?

StartFraction cosine squared (x) Over secant squared (x) EndFraction + StartFraction sine squared (x) Over secant squared (x) EndFraction = StartFraction 1 Over secant squared (x) EndFraction
StartFraction cosine squared (x) Over sine squared (x) EndFraction + StartFraction sine squared (x) Over sine squared (x) EndFraction = StartFraction 1 Over tangent squared (x) EndFraction
StartFraction cosine squared (x) Over tangent squared (x) EndFraction + StartFraction sine squared (x) Over tangent squared (x) EndFraction = StartFraction 1 Over tangent squared (x) EndFraction
StartFraction cosine squared (x) Over cosine squared (x) EndFraction + StartFraction sine squared (x) Over cosine squared (x) EndFraction = StartFraction 1 Over cosine squared (x) EndFraction