[" The number of distinct real roots of "[cos x cos x cos x]],[cos x sin x cos x],[cos x cos x sin x],[(B)2],[quad " (C) "1],[" (C) "1]

The number of distinct real roots of [[sin x , cos x , cos x ],[cos x , sin x , cos x],[cos x , cos x , sin x]] =0 in the interval -(pi)/(4) le x le (pi)/(4) is

Solve sin x+cos x=1 +sin x cos x

The number of distinct real roots of |(sinx, cosx, cosx),(cos x,sin x,cos x),(cos x,cos x,sin x)|=0 in the interval -(pi)/4 le x le (pi)/4 is

The number of distinct real roots of |(sinx, cosx, cosx),(cos x,sin x,cos x),(cos x,cos x,sin x)|=0 in the interval -(pi)/4 le x le (pi)/4 is

The number of distinct real roots of |(sinx, cosx, cosx),(cos x,sin x,cos x),(cos x,cos x,sin x)|=0 in the interval -(pi)/4 le x le (pi)/4 is

If sin x+cos x=1+sin x.cos x then x=

2tan2x = (cos x + sin x) / (cos x-sin x) - (cos x-sin x) / (cos x + sin x)

(1 + sin 2x + cos 2x )/( cos x + sin x ) = 2 cos x