Відповіді АЛГЕБРА: 1.21 (1-3)

1.21

1) f(x) = 1x- 5

D(y): x ≠ ± 5 x є (–∞; –5) U(–5; 5) U(5; ∞)

2) f(x) = 53+|x|

D(y): R

3) f(x) = 1x2- 4

D(y): x² – 4 > 0

(x – 2)(x + 2) > 0

x є (–∞; –2) U(2; ∞).

4) f(x) = 1x-1 + x+1x2+ 3x;

D(y): x ≠ 1

x² + 3x ≠ 0

x(x + 3) ≠ 0

x ≠ 0 x ≠ –3

x є (–∞; –3) U(–3; 0) U(0; 1) U (1; ∞).

5) f(x) = x+1x2+ x-2

D(y): x + 1 ≥ 0 x² + x – 2 ≠ 0

x ≥ – 1 x ≠ 1 x ≠ –2

x є [–1; 1) U (1; +∞).

6) f(x) = 31- x

D(y): 1 – x ≠ 0 x ≥ 0

x ≠ 1

x ≠ 1

x є [–1; 1) U (1; ∞)

7) f(x) = 1x + 1x-5;

D(y): x > 0 x є (0; 5) U (5; ∞)

x ≠ 5

8) f(x) = x+1 + -x

D(y): x + 1 ≥ 0 x ≥ –1 x є [–1; 0]

–x ≥ 0 x ≤ 0