Question

помогите пожалуйста!номер 1319, 1320, 1322

Answer 1

1319) a*b = 1*(-8) + 2*2 + 4*1 = 0
n*m = -2*2 + (-3)*3 +1*1 = -12

1320) 2p + q = 2*(1;-5;2) + (3,1,2) = (2;-10;4) + (3;1;2) = (5;-9;6)
3p-2q = 3*(1;-5;2) - 2(3;1;2) = (3;-15;6) - (6;2;4) = (-3;-17;2)

1322. а) a*b=1*1+2*0+(-2)*(-1) = 3
|a| = sqrt(1^2+(2)^2+(-2)^2) = sqrt (9) = 3
|b| = sqrt (1^2+0^2+(-1)^2) = sqrt(2)
cosa = 3/(3*sqrt (2)) = 1/sqrt (2)
a=45°

б) x*y = 3*0+2*4+(-2)*4=0
cosa=0
a=90°