## Trigonometry (11th Edition) Clone

$x=8.66$ feet
Graph $f(x)=\arctan{\left(\frac{15}{x}\right)}-\arctan{\left(\frac{5}{x}\right)}$ using a graphing utility, then identify its maximum point. Refer to the graph below. Thus, the value of $x$ that maximizes the viewing angle is $8.66$. Therefore, the student must sit next to the wall $8.66$ feet from the front of the classroom to maximize his viewing angle.