Using find

(i) 1

(ii)

(iii)

(iv)

(i) Using Identity

In the given expression

On substituting these values in the above identity, we get

=

(ii) Using Identity

In the given expression

On substituting these values in the above identity, we get

=

(iii) Using Identity

In the given expression

On substituting these values in the above identity, we get

=

(iv) Using Identity

In the given expression

On substituting these values in the above identity, we get

=

10