Question

The length of a rectangle is 4 units greater than its width, and the area of the rectangle can be expressed by the equation y=xsquared +4x. What is a resonable domain for this function?

Answer 1

X>0 and y>0 therefore, (0,≈)

Answer 2

Answer:

The domain of the function is $D=x|x>0$

Step-by-step explanation:

Given : The length of a rectangle is 4 units greater than its width, and the area of the rectangle can be expressed by the equation $y=x^2+4x$

To find : What is a reasonable domain for this function?

Solution :

Domain is defined as the all possible set of values in which function is defined.

We have given the area,

$y=x^2+4x$

We know, Area will never be negative so the value of x is always positive.

So, $y> 0$

$x^2+4x>0$

$x(x+4)> 0$

i.e. Either $x>0$

or $x+4> 0$

$x> -4$ but x>0

So, The value of x is defined from 0 to infinity.

The domain of the function is $D=x|x>0$