Write the given expression as a product of two trigonometric functions of different frequencies. sin7t-sin4t

2 * cos(11t/2) * sin(3t/2)

Explanation:
To answer this question, we will simply use the formula relating the difference between the sines as follows:
sin A - sin B = 2 * cos[(A+B)/2] * sin [(A-B)/2]

Now, we have:
A = 7t
B = 4t

Substitute with the givens in the formula as follows:
sin 7t - sin 4t = 2 * cos[(7+4)/2] * sin [(7-4)/2]
sin 7t - sin 4t = 2 * cos[11t/2] * sin [3t/2]

Hope this helps :)