sin(π - 3/4x) - sin(3π/2 - 3/4x)

Now let's apply the trigonometric identity sin(π - θ) = sinθ to the first term:

= -sin(3/4x) - sin(3π/2 - 3/4x)

Now let's apply the trigonometric identity sin(3π/2 - θ) = -cosθ to the second term:

= -sin(3/4x) - (-cos(3/4x))

= -sin(3/4x) + cos(3/4x)

Now we can simplify further by combining the terms:

= cos(3/4x) - sin(3/4x)

Therefore, the expression simplifies to cos(3/4x) - sin(3/4x).