1. The problem statement, all variables and given/known data let x=ksin(t). let k<1. let x'=x. let t'=t-kx. solve for x' as a function of t'. (this question has to do with relativity and deBroglie waves) 2. Relevant equations given above. 3. The attempt at a solution since t=t'+kx therefore x'=ksin(t'+kx). but I need x' as a function of t' only. I am ashamed to admit that such a simple linear problem has me stumped. if someone could give me a pointer I would be very glad.