Please help me answer

Answer:
[tex]after \: clear \: observation \: i \to: conclude \: \\ that \: the \: value \: of \: the \: angle \: R \: in \: terms \: of \: x \: = \\ the \: value \: of \: the \: angle \:U \: in \: terms \: of \: x \: .[/tex]
hence:
R(x) = U(x)