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fbrsk

We didn't touch the <u+v, w> = <u, w> + <v,w> property in class but it totally makes sense geometrically. Looking at it from how we talked about thinking of inner product like casting a shadow of one vector over the other, the addition of two vectors would cast a shadow whose length would be the summation of the individual shadows cast by u and v. I wish there was a way to upload an image!

meranara

I agree with the comment above about the shadows cast individually by u and v summed up would/should be equal to the shadow cast by the vector u+v. But, for some reason, this property seems a little off to me when just looking at it. What would be the case if the expression is <u+v,w+x>? Would it simplify to <u,w+x> + <v,w+x> = <u,w>+<u,x> + <v,w>+<v,x>?

Parker

I think that would be the case, meranara. If we substitute 'w+x' for a single variable representing that value, like 'z', then it becomes similar to the slide example to see how <u+v, z> becomes <u,z> + <v,z> which is equivalent to <u,w+x> + <v,w+x>. Since we know that the order of the vectors in an inner product don't matter, the steps from there are roughly the same as the ones in the slides.