Answer
$$\frac{15!}{5!}=6\times 7\times 8........\times 15$$
Work Step by Step
Write the Taylor's series for$sinx=x-\frac{1}{3!}x^3+\frac{1}{5!}x^5-.....$
For $f^{15}(x)=sinx^3=x^3-\frac{1}{3!}x^9+\frac{1}{5!}x^15-.....$
Now, $f^{15}(0)=sin(x^{3})^{15}(0)=\frac{15!}{5!}$
The required result is: $$\frac{15!}{5!}=6\times 7\times 8........\times 15$$
