[" 5.cot "10^(@)*cot20^(@)*cot60^(@)*cot70^(@)*cot80^(@)-(pi)/(4)pi/ pi(theta)/(theta)],[[" (a) "1," (b) "-1]]

cot10^(@)cot20^(@)cot60^(@)cot70^(@)cot80^(@)=

Find the value of cot10^(@).cot20^(@).cot60^(@).cot70^(@).cot80^(@) .

The value of cot10^@ cot20^@ cot60^@ cot 70^@ cot 80^@ is

cot((pi)/(4)+theta)cot((pi)/(4)-theta) is

4-cot((pi)/(4)+theta)cot((pi)/(4)-theta)=1

cot((pi)/(4)+theta)cot((pi)/(4)-theta)=?

cot((3 pi)/(2)-theta)+cot[2 pi+theta]=

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

cot((pi)/(4)-x)+cot((pi)/(4)+x)=4

lim_(theta rarr pi/2) (pi/2- theta)/(cot theta) =