Current Attempt in Progress

In the figure, point $P$ is at perpendicular distance $R=2\mathrm{.}18cm$ from a very long straight wire carrying a current. The magnetic field vec$(B)$ set up at point $P$ is due to contributions from all the identical current$-$length elements id vec$(s)$ along the wire. What is the distance $s$ to the element making $($a$)$ the greatest contribution to field vec$(B)$ and $($b$)12\mathrm{.}4\%$ of the greatest contribution?

$($a$)$ Number

Units

$($b$)$ Number

Units