What is the domain and range of sqrt((5x+6)/2)5x+62?

1 Answer
Mar 15, 2016

Answer:

Domain x in[-6/5,oo)x[65,)
Range [0,oo)[0,)

Explanation:

You must keep in mind that for the domain:

sqrt(y)->y>=0yy0

ln(y)->y>0ln(y)y>0

1/y->y!=01yy0

After that, you will be lead to an unequality giving you the domain.

This function is a combination of linear and square functions. Linear has domain RR. The square function though must have a positive number inside the square. Therefore:

(5x+6)/2>=0

Since 2 is positive:

5x+6>=0

5x>= -6

Since 5 is positive:

x>= -6/5

The domain of the functions is:

x in[-6/5,oo)

The range of the root function (outer function) is [0,oo) (infinite part can be proven through the limit as x->oo).