[" In "Delta ABC,b^(2)cos2A-a^(2)cos2B" is equal to "],[[" (a) "b^(2)-a^(2)," (b) "b^(2)-c^(2)],[" (c) "c^(2)-a^(2)," (d) "a^(2)+b^(2)+c^(2)]]

ln Delta ABC,b^(2)cos2A-a^(2)cos2B=

In Delta ABC, sum a^2 (cos^2 B-cos^2 C) =

In Delta ABC,(cos 2A)/(a^2) - (cos2B)/(b^2) = ......

In a Delta ABC,a(cos^(2)B+cos^(2)C)+cos A(c cos C+b cos B)=

In a Delta ABC,a(cos^(2)B+cos^(2)C)+cos A(c cos C+b cos B) is equal to

In a triangle ABC,cos^(2)A+cos^(2)B+cos^(2)C=

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))