6.2 Trigonometric Functions: Unit Circle Approach/43

Failed to parse (Conversion error. Server ("https://en.wikipedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle 2\sec({\frac {\pi }{4}})}

{\frac{\pi}{4})-\cos(45^{\circ}) = \frac{1}{2} - \frac{\sqrt{2}}{2} = \frac{1-\sqrt{2}}{2}