Determine where f is continuous

Determine where f is continuous. f(x) =-7e * sin (x) (Give your answer as an interval in the form (*, *). Use the symbol co for infinity, U for combining intervals, and an appropriate type of parenthesis "(", ")", "[", "I" depending on whether the interval is open or closed. Enter @ if the interval is empty. Express numbers in exact form. Use symbolic notation and fractions where needed.) XE