Given the functions defined by h(x)=x2−3x and k(x)=(x−2)−−−−−−√ , find kh(x) and write the domain of kh in interval notation

Answer :

MrRoyal

Answer:

[tex]k(h(x)) = \sqrt{x^2 - 3x - 2}[/tex]

[tex]x = (\infty, -0.56]\ u\ [3.56, \infty)[/tex]

Step-by-step explanation:

Given

[tex]h(x) = x^2 - 3x[/tex]

[tex]k(x) = \sqrt{x - 2}[/tex]

Solving (a): k(h(x))

[tex]k(x) = \sqrt{x - 2}[/tex]

Replace x with h(x)

[tex]k(h(x)) = \sqrt{h(x) - 2}[/tex]

Substitute:[tex]h(x) = x^2 - 3x[/tex]

[tex]k(h(x)) = \sqrt{x^2 - 3x - 2}[/tex]

Solving (b): The domain

For the function to be defined, the expression in the root must be greater than or equal to 0; i.e.

[tex]x^2 - 3x - 2 \ge 0[/tex]

Solve for x;

Using a calculator, we have:

[tex]x \le -0.56[/tex] and [tex]x \ge 3.56[/tex] --- approximated

So, the domain is:

[tex]x = (\infty, -0.56]\ u\ [3.56, \infty)[/tex]

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