Question #a7db9
1 Answer
Apr 24, 2017
#Sin 7x cos x - cos 7x sin x = sin(6x) #
Explanation:
We have:
#Sin 7x cos x - cos 7x sin x#
We can use the sine sum of two angles formula:
# sin(A-B) -= sinAcosB - cossinB#
so that:
#Sin 7x cos x - cos 7x sin x = sin(7x-x) #
#" " = sin(6) #
