" cot "-1(tan(3 pi)/(4))" prinuple value? "

If (3+cot80^(@)cot 20^(@))/(cot80^(@)+cot20^(@))=tan.(pi)/(k) , then the value of k is (where, (pi)/(k) is an acute angle)

If tan^(-1)4+cot^(-1)x=(pi)/(2), then value of x is

If alpha in (-(pi)/(2), 0) , then find the value of tan^(-1) (cot alpha) - cot^(-1) (tan alpha)

If alpha in (-(pi)/(2), 0) , then find the value of tan^(-1) (cot alpha) - cot^(-1) (tan alpha)

If alpha in (-(pi)/(2), 0) , then find the value of tan^(-1) (cot alpha) - cot^(-1) (tan alpha)

If alpha in (-(pi)/(2), 0) , then find the value of tan^(-1) (cot alpha) - cot^(-1) (tan alpha)

If alpha in(-(3 pi)/(2),-pi), then the value of tan^(-1)(cot alpha)-cot^(-1)(tan alpha)+sin^(-1)(sin alpha)+cos^(-1)(cot alpha) is equal to (a)2 pi+alpha(b)pi+alpha(c)0(d)pi-alpha

Find the principal values of each of the following: cot^(-1)(-(1)/(sqrt(3)))( ii) cot^(-1)((tan(3 pi))/(4))

Find the value of tan^(-1) (-tan.(13pi)/(8)) + cot^(-1) (-cot((19pi)/(8)))