With usual notations, in triangle `A B C ,acos(B-C)+bcos(C-A)+c"cos"(A-B)` is equal to(a) `(a b c)/R^2` (b) `(a b c)/(4R^2)` (c) `(4a b c)/(R^2)` (d) `(a b c)/(2R^2)`

With usual notations, in triangle ABC, a cos (B-C)+b cos (C-A)+c cos(A-B) is equal to

With usual notations,in a triangle ABC,acos(B-C)+b cos(C-A)+c cos(A-B) is equal to

With usual notations, in triangle ABC, a cos (B - C) + b cos (C - A) + c cos (A - B) is equal to

With usual notations,in triangle ABC,a cos(B-C)+b cos(C-A)+c cos(A-B) is equal to (a)(abc)/(R^(2)) (b) (abc)/(4R^(2)) (c) (4abc)/(R^(2)) (d) (abc)/(2R^(2))

(xv) a cos (B-C) + b cos (C-A) + c cos (A-B) = (4(Delta))/R

In a triangle A B C ,(r_1+r_2)/(1+cosC) is equal to (2a b)/(c"Delta") (b) ((a+b))/(c"Delta") (a b c)/(2"Delta") (d) (a b c)/("Delta"^2)

In a triangle A B C ,(r_1+r_2)/(1+cosC) is equal to (2a b)/(c"Delta") (b) ((a+b))/(c"Delta") (a b c)/(2"Delta") (d) (a b c)/("Delta"^2)

With usual notations in a triangle A B C , if r_1=2r_2=2r_3 then 4a=3b (b) 3a=2b 4b=3a (d) 2a=3b

With usual notations in a triangle A B C , if r_1=2r_2=2r_3 then 4a=3b (b) 3a=2b 4b=3a (d) 2a=3b

If ' O ' is the circum centre of the A B C and R_1,\ R_2,\ R_3 are the radii of the circumcircle of triangle O B C ,\ O C A\ a n d\ O A B respectively then a/(R_1)+b/(R_2)+c/(R_3) has the value equal to (a b c)/(2R^3) (b) (R^3)/(a b c) (c) (4)/(R^2) (d) (a b c)/(R^3)