` sin^(2) 66(1^(@))/2- sin^(2)23(1^(@))/2` किसके बराबर है ?

Options

A. `sin 47^(@)`
B. ` cos 47^(@)`
C. ` tan 2 x`
D. ` cot 2x`

Answer

b

Explanation

` sin^(2) 66(1^(@))/2 - sin ^(@) 23 (1^(@))/2`
` = sin^(2) [ (90^(@) - 23 (1^(@))/2)]- sin^(2)23(1^(@))/2`
` = cos^(2) 23 (1^(@))/2 - sin^(2) 23 (1^(@))/2`
` = cos (2 xx 23 (1^(@))/2)`
` = cos (2 xx 47^(@)/2)`
` = cos 47^(@)`