If a function f(x) defined by
f\left( x \right) = \left\{ {\matrix{
{a{e^x} + b{e^{ - x}},} & { - 1 \le x < 1} \cr
{c{x^2},} & {1 \le x \le 3} \cr
{a{x^2} + 2cx,} & {3 < x \le 4} \cr
} } \right.
be continuous for some , b, c R and f'(0) + f'(2) = e, then the value of of is :