If`(cosalpha+cosbeta+cosgamma)=0, sinalpha+sinbeta+singamma=0` then show that
`cos3alpha+cos3beta+cos3gamma=3cos(alpha+beta+gamma)`

If (cosalpha+cosbeta+cosgamma)=0, sinalpha+sinbeta+singamma=0 then show that sin3alpha+sin3beta+sin3gamma=3sin(alpha+beta+gamma)

If cosalpha+cosbeta+cosgamma=0 a n d a l so sinalpha+sinbeta+singamma=0, then prove that cos2alpha+cos2beta+cos2gamma =sin2alpha+sin2beta+sin2gamma=0

If cos alpha+ cos beta+ cos gamma + cos alpha cos beta cos gamma=0 , show that sin alpha (1+ cos beta cos gamma)=+- sin beta sin gamma .

If cos alpha+cos beta+cos gamma=0=sin alpha+sin beta+sin gamma , then (sin3alpha+sin3beta+sin3gamma)/(sin(alpha+beta+gamma)) is equal to

If cosalpha+2cosbeta+3cosgamma=sinalpha+2sinbeta+3singamma=0 , then the value of sin3alpha+8sin3beta+27sin3gamma is sin(a+b+gamma) b. 3sin(alpha+beta+gamma) c. 18"sin"(alpha+beta+gamma) d. sin(alpha+2beta+3)

if alpha+beta+gamma=2pi prove that cos^2alpha+cos^2beta+cos^2gamma-2cosalphacosbetacosgamma=1

If sin alpha + sin beta + sin gamma =3, then the value of (cos alpha + cos beta+ cos gamma) is-

if alpha , beta , gamma are in A>P show that cot =(sinalpha-singamma)/(cosgammacosalpha)

cos(beta-gamma)+cos(gamma-alpha)+cos(alpha-beta)=-3/2 show that cosalpha+cosbeta+cosgamma=0 and sinalpha+sinbeta+singamma=0 also cos(beta-gamma)=cos(gamma-alpha)=cos(alpha-beta)=-1/2 .

If cos (beta - gamma) + cos (gamma - alpha) + cos (alpha - beta) = -3/2, "show that", cos alpha + cos beta + cos gamma = 0 "and" sin alpha + sin beta + singamma = 0."Hence deduce that," cos (beta - gamma) = cos (gamma - alpha) = cos (alpha - beta) = -1/2.