Given \( \sin(\theta) = \frac{15}{17} \), we can use the Pythagorean identity \( \sin^2(\theta) + \cos^2(\theta) = 1 \) to find \( \cos(\theta) \):
\[
\cos(\theta) = \sqrt{1 - \sin^2(\theta)} = \sqrt{1 - \left(\frac{15}{17}\right)^2} = \frac{8}{17}.
\]
Now, we can use the values of \( \sin(\theta) \) and \( \cos(\theta) \) to calculate the trigonometric functions in the given expression and simplify to get \( \frac{23}{49} \).