If `A,B,C` are in A.P then `(sinA-sinC)/(cosC-cosA)=`

If three angles A,B and C are in A,P. Prove that cotB=(sinA-sinC)/(cosC-cosA) .

i) If sinA+sinB=sqrt(3)(cosB-cosA) , prove that: sin3A+sin3B=0 ii) If A,B and C are in arithmetic progression, then prove that: cotB=(sinA-sinc)/(cosC-cosA)

If A+C=2B, then (cosC-cosA)/(sinA-sinC)=

If A+C=2B, then (cosC-cosA)/(sinA-sinC)=

If in a /_\ ABC the altitude from the vertices A,B,C on opposite side are in H.P. then sinA,sinB,sinC are in (A) H.P. (B) Arithmetico-Geometric progression (C) A.P. (D) G.P.

A+C=2B then (cosC-cosA)/(sinA-sinC)=

If A, B, C are the angle of a triangle and |(sinA,sinB,sinC),(cosA,cosB,cosC),(cos^(3)A,cos^(3)B,cos^(3)C)|=0 , then show that DeltaABC is an isosceles.

If A, B, C are the angle of a triangle and |(sinA,sinB,sinC),(cosA,cosB,cosC),(cos^(3)A,cos^(3)B,cos^(3)C)|=0 , then show that DeltaABC is an isosceles.