Physics: If A=7.01-8.5j, B=-8.0i+8.1j+4.2k, and C=6.8i-7.2j, determine:?

If A=7.01-8.5j, B=-8.0i+8.1j+4.2k, and C=6.8i-7.2j, determine:


A(dot)(B+C)


(A+C)(dot)B


(B+A)(dot)C


Every letter is bold (which I think means a vector).





All (I think) I have is the magnitudes:


A=11.01


B=12.13


C=9.9





So for A(dot)(B+C)


B+C= -1.2i+.9j+4.2k


Magnitude of A+B: sqrt(1.2^2+.9^2+4.2^2)= 19.91


A(dot)(B+C)=11.01*19.91*cos(theta)


What’s theta (it is not given; not sure which angle; and a little rusty on trig)





OK, it should be obvious that I’m pretty clueless at this pint; can someone please help? Thanks.

Physics: If A=7.01-8.5j, B=-8.0i+8.1j+4.2k, and C=6.8i-7.2j, determine:?
I assume : a= i7.0 -j8.5


so adotb is -56i -68.85j


and adotc is 47.6i +61.2j


and bdot c is -54.4i -58.32j


and it's commutative and distributive