Chapter 2 - Acute Angles and Right Triangles - Section 2.3 Finding Trigonometric Function Values Using a Calculator - 2.3 Exercises - Page 63: 20

$\cos$ (90$^{\circ}$ - 3.69$^{\circ}$) = 0.06435814

$\cos$ (90$^{\circ}$ - 3.69$^{\circ}$) 90$^{\circ}$ - 3.69$^{\circ}$ = 86.31$^{\circ}$ Therefore: $\cos$ (90$^{\circ}$ - 3.69$^{\circ}$) = $\cos$ 86.31$^{\circ}$ $\cos$ 86.31$^{\circ}$ = 0.06435814 Therefore: $\cos$ (90$^{\circ}$ - 3.69$^{\circ}$) = 0.06435814