Evaluate :

`Sin70^(@) /Cos20^(@)` = ....

cos70^(@)+sin40^(@)=

Evaluate the following: cos80^(@)cos20^(@)+sin80^(@)sin20^(@)

The value of (sin 20^(@)cos70^(@)+ cos20^(@)sin70^(@))/(sin23^(@)"cosec"23^(@)+cos23^(@)sec23^(@)) is _________.

Evaluate (sin35^(@))/(cos55^(@))+(sec20^(@))/("cosec"70^(@)) .

The value of (sin 20^(@) cos 70^(@)+sin70^(@) cos 20^(@) ) is ……….. .

Find sin 20^@ -cos 70^@ .

Prove that (i) sin 70^(@) cos 10^(@) -cos 70^(@) sin 10^(@) =(sqrt(3))/(2) (ii) cos 50^(@) cos 10^(@) -sin 50^(@) sin 10^(@) =(1)/(2) (ii) cos 80^(@) cos 20^(@) + sin 80^(@) sin 20^(@) =(1)/(2) (iv) sin 36^(@) cos 9^(@) + cos 36^(@) sin 9^(@) =(1)/(sqrt(3))

What is the value of ((cos10^(@)+sin20^(@)))/((cos20^(@)-sin10^(@))) ?