IF `A+B=pi/2`, the maximum value of cos Acos B is

If A+B=90^(@) , show that the maximum value of: cos Acos B is (1)/(2) .

If A >0,B >0 and A+B=pi/3, the maximum value of tanAtanB is______

If A + B+ C = 3 pi//2 , then the value of cos 2 A + cos 2 B + cos2 C is equal to

If the maximum value of cos(cos x) is a and minimum value is b, then

Let A,B,C be the three angles such that A+B+C=pi , tan A.tan B=2 , then find the value of (cos A cos B)/(cos C)

Let A,B,C be the three angles such that A+B+C=pi , tan A.tan B=2 , then find the value of (cos A cos B)/(cos C)

In triangle ABC, /_C = (2pi)/3 then the value of cos^2 A + cos^2 B - cos A.cos B is equal