A) $1+2 x+4 x^{2}+8 x^{3}+\ldots$ Is the Maclaurin Series for What Function?
B)What Is Its

Essay

a) $1+2 x+4 x^{2}+8 x^{3}+\ldots$ is the Maclaurin series for what function?
b)What is its radius and interval of convergence (excluding possible endpoints)?
c)Use the Maclaurin series to determine $f^{\prime \prime \prime}(0)$ .