
Douglas B. answered 11/25/20
Differential equations tutor (former TA with masters in applied math)
Start with the definition of linear independence:
Because u1 and u2 are l.i., it follows that the only solution to c1*u1+c2*u2 = 0 is (c1,c2) = (0,0).
Now, set up the linear combination
d1*(A1u1+A2u2)+d2*(B1u1+B2u2) = 0 and show that (d1,d2) must be (0,0).
Enes Emre S.
is it answer sir ?11/25/20