1.5=1/cos(x) find x

1.5=1/cos(x) find x

$$\small{\text{$ \begin{array}{rcl} \dfrac{ 1 } { \cos{(x)} } &=& 1.5 \\\\ \dfrac{ 1 } { \cos{(x)} } &=& \dfrac{3}{2} \\\\ \cos{(x)} &=& \dfrac{2}{3} \\\\ \cos{(x)} &=& \dfrac{2}{3} \qquad | \qquad \pm\arccos{()}\\\\ x &=& \pm \arccos{ \left(\dfrac{2}{3} \right) }\\\\ x_{1,2} &=& \pm 48.1896851042\ensurement{^{\circ}}\\\\ \mathbf{x_1} & \mathbf{=} & \mathbf{48.1896851042\ensurement{^{\circ}} } \\\\ x_2 &=& -48.1896851042\ensurement{^{\circ}} \\\\ x_2 &=& -48.1896851042\ensurement{^{\circ}} + 360 \ensurement{^{\circ}} \\\\ \mathbf{x_2} & \mathbf{=} & \mathbf{311.810314896\ensurement{^{\circ}} } \end{array} $}}$$