Question

Даны вектора а(2;-6) b(-1;2)
Найти
1)|а|-|b|
2)|a-b|

Answer 1

| a | = √2^2+(- 6)^2 = √ 40 = 2√ 10
| b | = √ (- 1)^2 + 2^2 = √ 5
| a | - | b | = 2√ 10 - √ 5 
a - b = c (- 1-2; 2 - (- 6))  = c (- 3; 8)
| a - b | = √ (-3)^2+8^2  = √ 9 + 64 = √73