Question

please please ans asap urgent.............Find the domain of the following function: a) f(x) = root x^2 - root 9 ------ root is in upper both x^2 - 9 b) g(x) = 1 - I x - 4 I c) h(x) = x+7/ x^2 -6x+4

Answer 1

Answer:

a) f(x) = √(x² - 9)

domain: x²-9 ≥ 0

(x+3)(x-3) ≥ 0

So, x = (-♾️, -3] U[3,♾️]

b) domain: x belongs to R (real no.)

c) Here,

x²-6x +4 ≠ 0

x≠(6 ± √20)/2

x≠(3 ± √5)

x≠(3-√5), (3+√5)

So, x = (-∞, 3-√5) U (3-√5, 3+√5) U (3+√5,∞)