Answer with Step-by-step explanation:
We are given that
u+ v and u-v are orthogonal
We have to prove that u and v must have the same length.
When two vector a and b are orthogonal then

By using the property

We know that



Magnitude is always positive
When power of base on both sides are equal then base will be equal
Therefore,

Hence, the length of vectors u and v must have the same length.