Question

A function is defined as y = 3x + 5 with a domain of all real numbers greater than or equal to 5.What would be the range of the function?A All real numbersB All real numbers less than 20C All real numbers greater than or equal to 20D {20, 23, 26, 29, 32,...}

Answer 1

You have the following function:

y = 3x + 5

If the domain of the function are all real numbers greater or equal to 5, then the range of the function is determined by the values of y for x=5 and y for x => infinity.

Then, you have:

x = 5

y = 3(5) + 5

y = 15 + 5

y = 20

You can notice that as x approaches to infinity, y approaches to infinity too.

Hence, you can conclude that the rangle of the function:

C. All real numbers greater than or equal to 20