題組內容

I. (50 points) Fill in the following blanks.

6. If $$\sum{n=1}^{\infty} cn x^n$$ is the Taylor polynomial of order 4 generated by $$f(x) = \cos\left(\frac{x}{2}\right)$$ at 0, then the constant in front of $$x^4$$, $$c_4 =$$ __(6)__.