Unless otherwise specified, answers (numeric or algebraic) need not be simplified. If your answer is given as a decimal approximation, it should be correct to three places after the decimal point. Unless otherwise specified, the domain of a function f is assumed to be the set of all real numbers x for which f(x) is a real number. f(x)=⎧⎩⎨⎪⎪⎪⎪⎪⎪⎪⎪⎪⎪x2+kx−23x2+4x+3x3 +202ex2−exforx<−2for−2≤x<0for x=0forx>0Let f be the function defined above, where k is a constant.(a) For what value of k, if any, is f continuous at x=−2 ? Justify your answer.