The expression sin(57)cos(13) + cos(57)sin(13) can be simplified using the sine addition formula.
According to the sine addition formula, we know that:
sin(a + b) = sin(a)cos(b) + cos(a)sin(b)
In this case, we can let a = 57 and b = 13. So, applying the formula:
sin(57 + 13) = sin(57)cos(13) + cos(57)sin(13)
Therefore, the expression simplifies to sin(70).
To summarize, sin(57)cos(13) + cos(57)sin(13) = sin(70), showing how we can represent the given expression as the sine of an angle.