Which of the following is a rational number?

Let the closed interval [a , b] be the domain of function f. the domain of f(x - 3) is given by (a) the open interval (a , b) (b) the closed interval [a , b] (c) the closed interval [a - 3 , b - 3] (d) the closed interval [a + 3 , b + 3]

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

Acircle has a circumference of 28.36 units what is the diameter of the circle