To estimate $~2.001^4+2.001^2~$ using a local linear approximation, we would need to choose an appropriate function $~f~$ and a point on $~f~$ where $~x=a\,$. What function should we choose for $~f(x)~$ and what value would we choose for $~a\,$?
$f(x)=$
[[☃ expression 1]]
$a=\,$[[☃ input-number 1]]