please solve this...
cos 54 cos 36 + sin 54 sin 36
Answers
Answered by
5
heya...!!!!
we know that:-
cos(A - B) = cosAcosB + sinAsinB-----(1)
cos54cos36 + sin54cos36
from--(1)
we get,
cos(54 - 36) = cos18°
we know that:-
cos(A - B) = cosAcosB + sinAsinB-----(1)
cos54cos36 + sin54cos36
from--(1)
we get,
cos(54 - 36) = cos18°
Answered by
2
cos 18 is your answer
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pawanjhahaz1:
am i right?
np
what?
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