20cos(25)

解答

20 cos (2 5^{\circ})

18.12615 \dots

求解步骤

20 cos (2 5^{\circ})

整理为小数形式

= 18.12615 \dots

\frac{1}{sin ( 3 0 ^{\circ} )}

sin (20 π)

cos (arcsin (\frac{24}{25}))

sin (1 5^{\circ}) cos (1 5^{\circ}) + cos (1 5^{\circ}) sin (1 5^{\circ})

sin (\frac{π}{2}) - sin (\frac{π}{4})