If cosA + cosB `=4sin^(2)(C/2)`, then

If cosA=4/5 and cosB=12/13 , then find the values of cos(A+B) and sin(A-B) , where A , B ((3pi)/(2) to 2pi ) .

Let a and b be real numbers such that sina + sinb =1/sqrt(2) , cosa + cosb =sqrt(3)/2 , then

In Delta ABC,if cos A+sin A-2/(cosB+sin B)=0, then the value of ((a+b)/c)^4 is

If A+B+C=pi , prove that : cosA + cosB-cosC=4cos(A/2) cos(B/2) sin(C/2) -1

If cosA+cosB=m and sinA+sinB=n then sin(A+B)=

If cosA+cos^(2)A=1 , then prove that sin^(2)A+sin^(4)A=1 .

If sinA=sin B and cosA=cosB , then find the value of A in terms of Bdot

If in a triangle A B C ,(1+cosA)/a+(1+cosB)/b+(1+cosC)/c =(k^2(1+cosA)(1+cosB)(1+cosC)/(a b c) , then k is equal to (a) 1/(2sqrt(2)R) (b) 2R (c) 1/R (d) none of these

If cosA=3/4, then 32 sin (A/2) sin ((5A) /2)= ------------- (A) √11 (B) -√11 (C) 11 (D) -11

In triangle A B C , if cosA+cosB+cosC=7/4, t h e n R/r is equal to 3/4 (b) 4/3 (c) 2/3 (d) 3/2