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.
