If three angles A, B, and C are in A.P. ...

If three angles A, B, and C are in A.P. prove that: `cot B=(sin A-sin C)/(cos C-cos A)`

Verified by Experts

`RHS:`

`frac{sin A-sin C}{cos C-cos A}`

Using,

`sin c-sin d=2 sin frac{c-d}{2} cdot cos frac{c+d}{2}`

...

THE STRAIGHT LINES
RD SHARMA|Exercise Solved Examples And Exercises|488 Videos
TRIGONOMETRIC EQUATIONS
RD SHARMA|Exercise Solved Examples And Exercises|120 Videos

Similar Questions

Explore conceptually related problems

If the angles A,B,C are in A.P., prove that cot B=("sin" A-"sin" C)/(cos C-cos A)

If A,B,C are in A.P then (sin A-sin C)/(cos C-cos A)=

If A,B,C are in A.P., then correct relation is cot A=(sin B+sin C)/(cos C+sin B)

In any Delta ABC, prove that: (sin B)/(sin C)=(c-a cos B)/(b-a cos C)

If A , B , C are in A.P. then (sin A-sin C)/(cos C-cos A)= adot t a n B b. cot B c. t a n2B d. none of these

If the sides a,b and C of o+ABC are in A.P.,prove that 2sin(A)/(2)sin(C)/(2)=sin(B)/(2)a cos^(2)(C)/(2)+cos^(2)(A)/(2)=(3b)/(2)

In any Delta ABC ,prove that (sin B)/(sin C)=(c-a cos B)/(b-a cos C)

If sides a,b,c of the triangle ABC are in A.P,then prove that sin^(2)((A)/(2))cos ec2A;sin^(2)((B)/(2))cos ec2B;sin^(2)((c)/(2))cos ec2c are in H.P.

If A,B,C are the angles of a triangle then prove that cos A+cos B-cos C=-1+4cos((A)/(2))cos((B)/(2))sin((C)/(2))