" 12."(cos2A)/(a^(2))-(cos2B)/(b^(2))=(1)/(a^(2))-(1)/(b^(2))

(cos(2A))/(a^(2))-(cos(2B))/(b^(2))=(1)/(a^(2))-(1)/(b^(2))

In any DeltaABC , prove that (cos2A)/a^(2)-(cos2B)/b^(2)=(1/a^(2)-1/b^(2))

In any DeltaABC , prove that (cos2A)/a^(2)-(cos2B)/b^(2)=1/a^(2)-1/b^(2)

In triangleABC, (cos2A)/(a^(2))-(cos2B)/(b^(2))=

In triangleABC, (cos2A)/(a^(2))-(cos2B)/(b^(2))=

cos(2A)/a^2-cos(2B)/b^2 = 1/a^2-1/b^2

In any Delta ABC, prove the following: (a+b+c)(cos A+cos B+cos C)=2((a cos^(2))(1)/(2)(A+b cos^(2))(1)/(2)(B+cos^(2))(1)/(2)C)

If f(x)sin x cos xdx=(1)/(2(b^(2)-a^(2)))ln f(x)+c, then f(x) is equal to (1)/(a^(2)sin^(2)x+b^(2)cos^(2)x)(b)(1)/(a^(2)sin^(2)x-b^(2)cos^(2)x+b^(2)cos^(2)x+b^(2)cos^(2)x)(d)(1)/(a^(2)cos^(2)x-b^(2)cos^(2)x)

if cos^(-1)((1-a^(2))/(1+a^(2)))-cos^(-1)((1-b^(2))/(1+b^(2)))=2tan^(-1)x then x is:

(i) (1)/(sin^(2)a)-(1)/(sin^(2)B)=(cos^(2) a-cos^(2) B)/(sin^(2)a*sin^(2) B)