If `(cos13^(0)-sin13^(0))/(cos13^(0)+sin13^(0))+(1)/(cot148^(0))=k,` then `(k^(2))/(16)` is equal to "

If ( cos 13^(@)+sin13^(@))/(cos13^(@)-sin13^(@))=tan A , then A=_________

(Cos13-Sin13)/(Cos13+Sin13)+(1)/(Cot148^@)=

If cos25^(0)+sin25^(0)=K, then cos50^(@) is equal to

Prove that : (cos13^@+sin13^@)/(cos13^@-sin13^@) =tan 58^@ .

" The value of ((sin17^(@))(cos13^(@))+(cos17^(@))(sin13^(@)))/((cos23^(@))(cos37^(@))-(sin157^(@))(sin37^(@))) is equal to