![](https://merykhachatryan584486446.wordpress.com/wp-content/uploads/2023/02/image-5.png?w=684)
ա) F = √ (x – 1) + √(3 – x) ≥ 0
√ (x – 1) ≥ 0
x – 1 ≥ 0
x ≥ 1
√(3 – x) ≥ 0
x – 3 ≥ 0
x ≥ 3
[1; 3]
բ) F = √ (x – 1) – √(3 – x) ≥ 0
√ (x – 1) ≥ 0
x – 1 ≥ 0
x ≥ 1
√(3 – x) ≥ 0
x – 3 ≥ 0
x ≥ 3
[1; 3]
![](https://merykhachatryan584486446.wordpress.com/wp-content/uploads/2023/02/20230226_213023.jpg?w=890)
![](https://merykhachatryan584486446.wordpress.com/wp-content/uploads/2023/02/image-6.png?w=460)
ա) x2 – 8x + 21 = (x2 – 24x + 16) + 5 = (x – 4) + 5