Expert QA Done lu f1 The angle e between the ve Solutionv3i4

Expert Q&A; Done lu.) f.)-1 The angle e between the ve

Solution

v=3i+4j, w=-2i+6j

| v |= sqrt(3²+4²) =sqrt 25=5

| w | =sqrt((-2)²+6²) =sqrt 40 = 2sqrt 10

b. w-v= <-2-3,6-4> =<-5,2>=-6i +2j

e. v.w= 3*(-2) +4*6 =-6 +24=18

f. v.w = | v | |w | cos theta

18 = 5*2 sqrt10 cos theta

18=10 sqrt 10 cos theta

cos theta=18/10sqrt10

theta=cos^-1(18/10sqrt10)

theta=55.30 degree