Question

Даны векторы c -1;5;2 и b 2;-3;1 найдите |c-2b|

Answer 1

с - 2b = (-1;5;2) - 2(2;-3;1) = (-1-2*2; 5+2*3; 2-2*1) = (-5;11;0)
|с - 2b| = √(5² + 11² + 0²) = √(25 + 121) = √146