Question

domain of

$\sqrt{4 - x}$
​

Answer 1

Answer:

( - ∞ , 4]

Step-by-step explanation:

For this function to exist, 4 - x must be a non-negative number.

Since roots of -ve numbers do not exist in real number-line, 4 - x must be a positive value(greater than 0) or 0.

⇒ 4 - x ≥ 0

⇒ 4 ≥ x

Therefore, x is any number lesser or equal to 4.

 x lies in ( -∞ , 4]

Answer 2

Here ,

We are unable to get the square root for the non negative number so value must be ≥.

→ 4 - x ≥ 0

→ 4 ≥ x

→ x ≤ 4

Hence ,

• x is equals to or lesser than 4.

x lies in ( -∞ , 4 ]