If A,B,C are angles made by a vector OX,OY,OZ then calculate - sin^2A+sin^2B+sin^2C and - cos2A+cos2B+cos2C?

I think you must be leaving out some information.


You can use identities like cos2a = cos^a - sin^2a to state the second in terms of cosa and sina, but that's about all I can glean from this at all.

If A,B,C are angles made by a vector OX,OY,OZ then calculate - sin^2A+sin^2B+sin^2C and - cos2A+cos2B+cos2C?
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Reply:...what?
Reply:sin^2A+sin^2B+sin^2c = 1 - cos^2A +1 - cos^2B + 1 - cos^2C


= 1+1+1 -(cos^2A+cos^B+cos^2C)


= 3- (1)


= 3-1


= 2


cos2A+cos2B+cos2C = 2cos^2A-1 +2cos^2B-1+2cos^2C-1





= 2(cos^2A+cos^2B+cos^2C)- (1+1+1)


=2(1) -(3)


=2 -3


= -1