Question

If f(x)=√4x+9+2, which inequality can be used to find the domain of f(x)?

Answer 1

Answer:

[-11/4, ∞)

Step-by-step explanation:

Given :

y = √(4x + 9 + 2)

Simplifying :

y = √(4x + 11)

Now, the term in the bracket has to be greater than or equal to 0 to be real.

Hence,

⇒ 4x + 11 ≥ 0

⇒ 4x ≥ -11

⇒ x ≥ -11/4 [Lower limit]

Infinity will be the upper limit as the numbers increase indefinitely.

The domain will be :

⇒ [-11/4, ∞)

Answer 2

• y=√4x+9+2
• y=√4x+11

As it's a square root the underroot value must be greater than or equal to 0

So

let's find out the domain

• √4x+11≥0
• 4x+11≥0
• 4x≥-11
• x≥-11/4

Domain

• [-11/4,oo)