What is the value of cos `15^(@)`?

What is the value of |{:(cos 15^(@),sin 15^(@)),(cos 45^(@),sin 45^(@)):}|xx|{:(cos 45^(@),cos 15^(@)),(sin 45^(@),sin 15^(@)):}| ?

What is the value of sin 15^(@) ?

What is the value of cos15^(@)-cos165^(@) ?

What is the value of (cos15^(@)+cos45^(@))/(cos^(3)15^(@)+cos^(3)45^(@))

Find the value of cos 15^(@) .

find value of cos 15^@

What is the value of Tan 15^@ ?

Find the value of cos15^@