=v2u2 + v3u3
2.<cu,v> = cu1v2+cu2v2
4.a) <u,u>=u22 + u32
greater than or equal to zero as u2^2 greater than or equal to zero and u3^2 is greater than or equal to zero
b) <u,u>=0 then u2=0 and u3=0.
Somehow ive wrongly proved all the axioms :S im assuming this does not define an inner product as it does not include u1 and v1 in the inner product, therefore cannot be an inner product in R^3. I would greatly appreciate anyone looking over my work to help me! Thanks