I have a question in numerical analysis and I do not know where to put it so I post it here ok the question

Find the largest interval in which $\displaystyle p^{*}$ must lie to approximate $\displaystyle p$ with relative error at most $\displaystyle 10^{-4}$ for each value of p

$\displaystyle a.\pi \quad\quad b.e \quad\quad c.\sqrt{2} \quad\quad d.\sqrt[3]{7}$

I know that relative error = $\displaystyle \frac{\mid p-p^*\mid}{\mid p\mid}$

$\displaystyle p^*$ is the approximation to for $\displaystyle p$

can anyone tell me how I can solve questions like this ..........

Thanks