In any `Delta ABC,` show that `cos A+ cos B+ cos C = (1+ (r )/(R )).`

In a triangle ABC, cos 3A + cos 3B + cos 3C = 1 , then then one angle must be exactly equal to

If sinA=1/2 , show that 3 cos A - 4 cos^(3) A= 0

In a triangle ABC, sin A- cos B = Cos C , then angle B is

In a Delta ABC, c cos ^(2)""(A)/(2) + a cos ^(2) ""(C ) /(2)=(3b)/(2), then a,b,c are in

In any Delta ABC, prove the following : r_1=rcot(B/2)cot(C/2)

In DeltaABC,if cos A+ sin A -(2)/(cos B + sin B) =0, then (a+b)/c is equal to

For any triangle ABC, prove that : a(cosC-cosB)=2(b-c)cos^(2)""(A)/(2)

D is midpoint of BC in Delta ABC such that AD and AC are perpendicular, Show that Cos A Cos C = (2 (c^2-a^2))/(3ac)

Statement I In a Delta ABC, if a lt b lt c and ri si inradius and r_(1), r_(2) ,r_(3) are the exradii opposite to angle A,B,C respectively, then r lt r_(1) lt r_(2) lt r_(3). Statement II For, DeltaABC r_(1)r_(2)+r_(2)r_(3)+r_(3)r_(1)=(r_(1)r_(2)r_(3))/(r)

For any triangle ABC, prove that : a(bcosC-c cosB)=b^(2)-c^(2)