If A = 30°, verify that:

(i)


(ii)


(iii)

(i) To prove:- sin 2A =


A = 30°


To show:- sin 60° =


Consider L.H.S. = =


=


= =


= √3/2


= sin 60° = R.H.S.


R.H.S. = L.H.S.


Hence, verified.


(ii) To show:- cos 2A =


A = 30°


To show:- cos 60° =


Consider R.H.S. = =


= 2/4 = 1/2 = cos 60° = L.H.S.


R.H.S. = L.H.S.


Hence, verified.


(iii) To show:- tan2A =


A = 30°


To show:- tan 60° =


Consider R.H.S. = = =


= 3/√3 = √3


= tan 60° = L.H.S.


R.H.S. = L.H.S.


Hence, verified.


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