Home
Class 11
MATHS
If cos alpha + 2cos beta+ 3 cos gamma = ...

If `cos alpha + 2cos beta+ 3 cos gamma = 0, sin alpha + 2sin beta +3 sin gamma= 0 and alpha + beta + gamma= pi`, then `sin 3alpha + 8 sin 3 beta + 27 sin 3 gamma`=

A

`-18`

B

0

C

3

D

9

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Similar Questions

Explore conceptually related problems

Evaluate |[cos alpha cos beta, cos alpha sin beta, -sin alpha],[ -sin beta, cos beta, 0],[ sin alpha cos beta, sin alpha sin beta, cos alpha]|

If cos alpha+cos beta=1/3 and sin alpha+sin beta=1/4 ,show that tan((alpha+beta)/2)=3/4

If alpha, beta, gamma in [0, pi]"and if" alpha, beta, gamma are in AP, then (sin alpha - sin gamma)/(cos gamma - cos alpha) is equal to

If alpha+beta =pi//2andbeta+gamma=alpha , then tanalpha equals

If a, b and c are in geometric progression and the roots of the equations ax^(2)+2bx+c=0 are alpha and beta and those cx^(2)+2bx+a=0 are gamma and delta , then : a) alpha ne beta ne gamma ne delta b) alpha ne beta and gamma ne delta c) alpha=abeta=cgamma=cdelta d) alpha=beta and gamma ne delta

Evaluate Delta=|[0, sin alpha, -cos alpha],[ -sin alpha, 0 , sin beta],[ cos alpha, -sin beta, 0]|

If a line makes angles alpha ,beta , gamma with the co-ordinates axes, then cos 2alpha +cos 2beta +cos 2gamma is :

If sin theta = 3 sin (theta + 2 alpha) , then the value of tan (theta + alpha) + 2 tan alpha is

A line makes acute angles of alpha, beta and gamma with the co-ordinae axes such that cos alpha cos beta = cos beta cos gamma = (2)/(9) and cos gamma cos alpha = (4)/(9), then cos alpha + cos beta + cos gamma is equal to : a) (25)/(9) b) (5)/(9) c) (5)/(3) d) (2)/(3)