## Precalculus (6th Edition) Blitzer

The solution is $\underline{x=1.7303,4.8719}.$
We have to compute the value: \begin{align} & \tan x=-6.2154 \\ & x={{\tan }^{-1}}\left( -6.2154 \right) \end{align} We have to calculate the equation using a calculator in radian mode: ${{\tan }^{-1}}\left( +6.2154 \right)\approx 1.4113$ And the tangent value is negative in II and IV quadrants. So, \begin{align} & x\approx \pi -1.4113 \\ & \approx 3.14159-1.4113 \\ & \approx 1.7303 \end{align} And the other value will be: \begin{align} & x\approx 2\pi -1.4113 \\ & \approx 2\times 3.14159-1.4113 \\ & \approx 4.8719 \end{align}