Cos 75 cos 15-sin 75 sin 15=0
Answers
Answered by
1
Answer:
cos(75+15)
=cos90
=0
.............
Answered by
2
Cos 75 degree = root3 - 1 by 2root2
cos 15 degree = root3 +1 by 2root2
sin 75 degree = root 3 +1 by 2root2
sin 15 degree = 3root 3 -1 by 2root2
so now just subtitue their values
2/2root2 - 2/2root2 = 0
hence proved
Or you can simply use the cos(a+b) formula
it will be
cos(75+15) = cos(90) =0
but you wanted proof so i solved it
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