Question

Срочно помогите 10А09 пожалуйста

Answer 1

a) a*b = (2m+3n)*(m-2n) = 2m^2+3nm-4mn-6n^2=2m^2-mn-6n^2
m^2 = |m|^2 = 1^2=1
n^2 = |n|^2 = 3^3=9
mn = |m| |n| cos(m^n) = 1*3*cos150 = 3*sqrt(3)/2
a*b = 2*1-6*9 - 3sqrt(3)/2 = -52 - 3sqrt(3)/2

б) a*b = (2m-3n)*(m+2n) = 2m^2-3nm+4mn-6n^2 = 2m^2+mn-6n^2
m^2 = |m| = 1^2=1
n^2=|n|^2 = 3^2=9
mn = |m| |n| cos(m^n) = 1*3*cos135 = 3*sqrt(2)/2
a*b= 2*1-6*9 - 3sqrt(2)/2 = -52 - 3sqrt(2)/2