Question

Find the angle between each of the following pairs of vectors A⃗ =Axi^+Ayj^ and B⃗ =Bxi^+Byj^.
Ax1= -3.20, Ay1= 4.40; Bx1= 2.70, By1= -3.10
i know this is dot prodoct but the calculater just keep saying error

Answer 1

what is the error?

Answer 2

\(a\cdot b = -3*2.70+4.40*-3.10 = -21.74\)
so
\(\theta=\cos^{-1}(\frac{-21.74}{\sqrt{3^2+4.4^2}*\sqrt{2.7^2+3.1^2}})=172^{\circ}\)

Answer 3

boo at post and leave...