Question

2tanθ+5=0
Use a calculator to solve the following equation on the interval 0 less than or equals theta less than 2 pi0≤θ<2π.

Answer 1

$\bf 2tan(\theta)+5=0\implies 2tan(\theta)=-5\implies tan(\theta)=-\cfrac{5}{2} \\\\\\ tan^{-1}[tan(\theta)]=tan^{-1}\left( -\cfrac{5}{2} \right)\implies \measuredangle \theta=tan^{-1}\left( -\cfrac{5}{2} \right)$

plug that in your calculator then, keep in mind that, if your calculator is in Radian mode, you'll get a radian angle value, if in Degree mode, you'll get a degree value