8sin^4(x)

To simplify the expression 8sin^4(x), we can start by using the trigonometric identity: sin^2(x) = (1 - cos(2x))/2.

Let's substitute this identity into the expression:

8sin^4(x) = 8(sin^2(x))^2 = 8[(1 - cos(2x))/2]^2

Next, we can simplify further by squaring both the numerator and the denominator inside the square brackets:

8[(1 - cos(2x))/2]^2 = 8(1 - cos(2x))^2/4

Now, we can simplify the expression inside the parentheses by expanding the square:

8(1 - cos(2x))^2/4 = 8(1 - 2cos(2x) + cos^2(2x))/4

Finally, we can simplify the expression further by dividing both the numerator and the denominator by 4:

8(1 - 2cos(2x) + cos^2(2x))/4 = 2(1 - 2cos(2x) + cos^2(2x))

Therefore, the simplified form of 8sin^4(x) is 2(1 - 2cos(2x) + cos^2(2x)).