If `cos(A+B)sin(C+D)=cos(A-B)sin(C-D)` ,
prove that cot A cot B cot C= cot D.

If A+B=45^(circ) , prove that (cot A-1)(cot B-1) = 2

Prove that cot x cot 2 x-cot 2 x cot 3 x-cot 3 x cot x=1

Prove that cotx cot2x -cot2xcot3x-cot3xcotx=1

If A+ B + C = pi, then cos^(2) A + cos ^(2) B + cos ^(2) C is equal to : A) 1 - cos A cos B cos C B) 1 - 2 cos A cos B cos C C) 2 cos A cos B cos C D) 1 + cos A cos B cos C

Prove that (cos 7 x+cos 5 x)/(sin 7 x-sin 5 x)=cot x

If cos theta, sin phi, sin theta are in G.P., then prove that roots of x^(2)+2 cot phi x+1=0 are real

If tan(cos^(-1)x)=sin(cot^(-1)""(1)/2) , then find the value of x.

int( d x)/(sin ^(2) x cos ^(2) x) equals a) tan x+cot x+C b) tan x-cot x+C c) tan x cot x+C d) tan x-cot 2 x+C

Prove that sqrt((1+cosA)/(1-cos A))=cosecA+cot A

If A+B+C=180^@ ,prove that cos^2A+cos^2B+cos^2C=1-2cos Acos B cos C .