What is the value of cot `(-870^(@))`?

State which of the following is the value of cot(-870^@) ?

What is the value of cot(90^@+75)^@ ? cot(90^@+75)^@ का मान क्या है?

What is the value of cot^(2) 72^(@)-cosec^(2)72^(2) ?

What is the value of cot((-5pi)/4) ?

What is the value of cot 45^(@) +cosec 60^(@)?

If cot A=[(sin B)/((1- cos B))] , then what is the value of cot 2A ?

What is the value of cot35^@ cot40^@ cot45^@ cot50^@ cot55^@ ? cot35^@ cot40^@ cot45^@ cot50^@ cot55^@ का मान क्या है ?

What is the value of ((1)/(3)-cot60^(@)) ?