If `A + B + C = pi` and `Sigma cos A cosec B cosec C = k` , then k=

If A + B + C = pi , prove that cos A cosec B cosec C + cos B cosec C cosec A + cos C cosec A cosec B = 2 .

If A+B+C =pi , show that cot A + cot B+cot C-cosec A *cosec B* cosec C = cot A*cot B*cot C .

" In a triangle "ABC" ,if "2cos A=sin B" cosec "C" then "

If A+B+C=pi, prove that cot A+cot B+cot C-csc A.cosec B.csc C=cot A*cot B*cot C

In Delta ABC , angle B = 90 ^(@) Evaluate : cosec A cos C - sin A sec C .

In the triangle ABC, If "cosec"^(2) A + " cosec "^(2)B + " cosec "^(2) C=4 , show that the triangle is equilateral.

In a Delta ABC,angle B=90^(@),AB=12 cm and BC = 5cm find (i) cos A \ \(ii) "cosec"A\ \(iii) cos C\ \(iv) "cosec C".

A triangle ABC is right angled at B, find the value of (sec A . cosec C - tan A . cot C)/(sin B)

The angle of elevation of the top of a hill from each of the verticles A,B,C of a horizontal triangle is alpha . The height of the hill is 1. b tan α cosec β 2. 1 2 a tan α cosec A 3. 1 2 c tan α cos e c C 4. none of these