(A2-5)  We have two x-coordinate transformation equations:

These, must both be simultaneously true at a specific point in space and time. So:

• First, Substitute the expression for xN into the expression for xC, which will eliminate xN from the expression.

• Now what we’re aiming for is an expression for tN, so rearrange to make tN the subject.

• This expression can now be cleaned up and simplified. See if you can do this.