Use the definition of continuity and the properties of limits to show that the function is continuous at the given number a. (x) = ( x + 4x]) , a=-1 lim /x) = lim x+-1 = lim by the power law x -+ -1 = lim (x) + lim by the sum law X - -1 = lim (x) + * +-1 lim (x3, ) by the multiple constant law = by the direct substitution property Find /-1). K-1) = Thus, by the definition of continuity, F is continuous at a = -1