`cos^2 72^0-sin^2 5 4^(@)=`

Find the value of cos^(2)72^(@) - sin^(2) 54^(@) .

cos ^ (2) 72 ^ (0) -sin ^ (2) 54 ^ (@) =

The value of (sin^2 52^@+2+sin^2 38^@)/(4cos^2 43^@-5+4cos^2 47^@) is : (sin^2 52^@+2+sin^2 38^@)/(4cos^2 43^@-5+4cos^2 47^@) का मान ज्ञात करें:

Prove that (i) "sin"^(2) 24^(@) - sin^(2) 6^(@) =((sqrt(5)-1))/(8) " "(ii) "sin"^(2) 72^(@) - cos^(2) 30^(@) =(sqrt(5)-1)/(8)

3 cos72^(@)-4" sin"18^(@)=

Evaluate: ((cos 47^(@))/(sin 43^(@)))^(2)+((sin72^(2))/(cos 18^(@)))^(2)-2cos^(2)45^(@)

sin^2 17.5^@+sin^2 72.5^@ is equal to

3 cos 72 ^(@) -4 sin ^(3) 18^(@) = cos 36 ^(@).

The value of (cos ^(6)5^(@)-15 cos ^(4) 5^(@) sin ^(2)5^(@)+15 cos ^(2)5^(@)sin ^(4) 5^(@)-sin ^(6)5^(@)) is equal to-