compound angle formula — An Etymological Dictionary of Astronomy and Astrophysics

compound angle formula

دیسول ِ زاویه‌ی ِ همنات

disul-e zaviye-ye hamnât

Fr.: formule d'angle composé

One of eight equations that give the → trigonometric functions of → compound angles.

sin(A± B) = sinA.cosnd angleB± cosA.sinB

cos(A + B) = cosA.cosB - sinA.sinB

cos(A - B) = cosA.cosB + sinA.sinB

tan(A + B) = (tanA + tanB)/(1 - tanA.tanB)

tan(A - B) = (tanA - tanB)/(1 + tanA.tanB).

See also: → compound; → angle; → formula.

An Etymological Dictionary of Astronomy and Astrophysics