Find the domain of real valued functions of real variable f (x) =\(\sqrt{\dfrac{{x-2}}{3-x}} \)

Asked by Aaryan | 1 year ago |  95

1 Answer

Solution :-

f (x) = \(\sqrt{\dfrac{{x-2}}{3-x}} \)

We know the square root of a real number is never negative.

f (x) takes real values only when x – 2 and 3 – x are both positive and negative.

(a) Both x – 2 and 3 – x are positive

x – 2 ≥ 0

x ≥ 2

3 – x ≥ 0

x ≤ 3

Hence, x ≥ 2 and x ≤ 3

x ∈ [2, 3]

(b) Both x – 2 and 3 – x are negative

x – 2 ≤ 0

x ≤ 2

3 – x ≤ 0

x ≥ 3

Hence, x ≤ 2 and x ≥ 3

However, the intersection of these sets is null set. Thus, this case is not possible.

Hence, x ∈ [2, 3] – {3}

x ∈ [2, 3]

Domain (f) = [2, 3]

Answered by Aaryan | 1 year ago

Related Questions

Let R = {(a, b) : a, b, ϵ N and a < b}.Show that R is a binary relation on N, which is neither reflexive nor symmetric. Show that R is transitive.

Class 11 Maths Relations and Functions View Answer

Let R = {(x, x2) : x is a prime number less than 10}.

(i) Write R in roster form.

(ii) Find dom (R) and range (R).

Class 11 Maths Relations and Functions View Answer