If the function is f(t) =, then (a) the numerator tan(t) is defined everywhere except t = , k = 0, +/-1, +/-2, . . . (b) the denominator is defined everywhere and is not zero, except of the points t such that sin(t) = cos(t), or tan(t) = 1, that are t = , k = 0, +/-1, +/-2, . . . THEREFORE, the given function domain is the set of all real numbers except t = , k = 0, +/-1, +/-2, . . . and t = , k = 0, +/-1, +/-2, . . .