4. Find a power series for the function, centered at c, and determine the interval of convergence. a) f (x) = _ 2 7x+3' ; c = 5 b ) f ( x ) = - 2x3 + 3' -; C=0 c) f ( x ) = 4x - 7 ; C=0 2x2 +3x - 2' d) f ( x) =- 14x + 38 6x2 +31x +35 c=3 e) f (x) = In(1+4x ); c=0 f ) f (x) = xarctan (7x'); c=0