The Taylor series for $f(x) = \cos(x)$ at a = $\frac{\pi}{4}$ is $\displaystyle \sum_{n=0}^\infty c_n( x- \frac{\pi}{4} )^n.$
Find the first few coefficients.
$c_0 =$
$c_1 =$
$c_2 =$
$c_3 =$
$c_4 =$