ANSWER
[tex]B=63\degree[/tex]
EXPLANATION
We want to solve the trigonometric equation;
[tex]tan^2(B)=4[/tex], where [tex]0\degree \le B \le 90\degree[/tex].
Taking square root of both sides gives,
[tex]tan(B)=\pm \sqrt{4}[/tex]
[tex]tan(B)=\pm 2[/tex]
Since B is in the first quadrant, we proceed with;
[tex]tan(B)=2[/tex], because the tangent ratio is positive in the first quadrant.
[tex]\Rightarrow B =arctan(2)[/tex]
[tex]\Rightarrow B =63.43\degree[/tex].
Correct to the nearest degree,
[tex]B =63\degree[/tex]
