If `A + B + C=pi`, then find the minimum value of `cot^2A + cot^2B + cot^2C`

Find the minimum value of f(x)= pi^2/(16 cot^-1 (-x)) - cot^-1 x

Let a, b, c , d he real numbers such that a + b+c+d = 10 , then the minimum value of a^2 cot 9^@+b^2 cot 27^@+c^2 cot 63^@+d^2 cot 81^@ is sqrtn ,(n in N) find n.

If tan A + cot A = 5, find the value of tan^2 A + cot^2 A .

Find the value of : cot^-1 (cot((5pi)/4))

if ABC is a triangle and tan(A/2), tan(B/2), tan(C/2) are in H.P. Then find the minimum value of cot(A/2)*cot(C/2)

In a triangle ABC if b+c=3a then find the value of cot(B/2)cot(C/2)

Find the value of : cot^(-1)cot((5pi)/4)

If tanA-tan B=x , and cot B-cotA=y , then find the value of cot(A-B) .

In a Delta ABC if 9 (a^2 + b^2) = 17c^2 then the value of the (cot A + cot B) / cotC is

In a Delta ABC if 9 (a^2 + b^2) = 17c^2 then the value of the (cot A + cot B) / cotC is