`cos45^@ cos60^@-sin45^@sin60^@=(sqrt3-1)/(2sqrt2).`

cos45^(@)cos60^(@)-sin45^(@)sin60^(@)=(sqrt(3-1))/(2sqrt(2))

Prove that (cos45^(@)-cos75^(@))/(sin45^(@)+sin75^(@))=2-sqrt3

Evaluate: cos 45 cos 60 - sin 45 sin 60

((cos30^(@)+sin60^(@))/(1+cos60^(@)+sin30^(@)))=(sqrt(3))/(2)

Prove that cos^2 45^@-sin^2 15^@=sqrt3/4

sin45^@*cos45^@+sqrt3sin60^@ = …………..

frac(cos60^@ + sin 60^@)(cos60^@- sin 60^@) is equal to (A) -(sqrt3 +2) (B) -1 (C ) (sqrt3 -2) (D) (sqrt3 + 2)

Evaluate : (i) sin^(2)30^(@)-2cos^(3)60^(@)+3tan^(4)45^(@) (ii) (cos0^(@)+sin45^(@)+sin30^(@))(sin90^(@)-cos45^(@)+cos60^(@))

Prove that: (cos30^(@)+sin60^(0))/(1+cos60^(@)+sin30^(@))=(sqrt(3))/(2)