## Precalculus (6th Edition) Blitzer

The solution on the interval $[0,2\pi )$, correct to four decimal places, is $1.8925$ or $5.0341$.
We have to calculate the equation using a calculator in radian mode: $\theta ={{\tan }^{-1}}3\approx 1.2490$ Since, the tangent is negative in quadrants II and IV, Thus, $x\approx \pi -1.2490\$ As, the value of $\pi$ is 3.14159. Thus, the value of $x$ is: \begin{align} & x\approx 3.14159-1.2490 \\ & \approx 1.8925 \end{align} or $x\approx 2\pi -1.2490\$ The value of $\pi$ is 3.14159. Thus, the value of $x$ is: \begin{align} & x\approx 2\times 3.14159-1.2490 \\ & \approx 6.28318-1.2490 \\ & \approx 5.0341 \end{align} Therefore, the solution of the equation $\tan x=-3$, correct to four decimal places, on the interval $[0,2\pi )$ is $1.8925$ or $5.0341$.