3.414*cos(45)

解

3.414 \cdot cos (4 5^{\circ})

\frac{1707 2}{1000}

十進法表記

2.41406 \dots

解答ステップ

3.414 cos (4 5^{\circ})

= \frac{1707}{500} cos (4 5^{\circ})

次の自明恒等式を使用する:

cos (4 5^{\circ}) = \frac{2}{2}

cos (4 5^{\circ})

cos (x)

36 0^{\circ} n

循環を含む周期性テーブル:

x 0 \frac{π}{6} \frac{π}{4} \frac{π}{3} \frac{π}{2} \frac{2 π}{3} \frac{3 π}{4} \frac{5 π}{6} cos (x) 1 \frac{3}{2} \frac{2}{2} \frac{1}{2} 0 - \frac{1}{2} - \frac{2}{2} - \frac{3}{2} x π \frac{7 π}{6} \frac{5 π}{4} \frac{4 π}{3} \frac{3 π}{2} \frac{5 π}{3} \frac{7 π}{4} \frac{11 π}{6} cos (x) - 1 - \frac{3}{2} - \frac{2}{2} - \frac{1}{2} 0 \frac{1}{2} \frac{2}{2} \frac{3}{2}

= \frac{2}{2}

= \frac{1707}{500} \cdot \frac{2}{2}

簡素化

\frac{1707}{500} \cdot \frac{2}{2} : \frac{1707 2}{1000}

\frac{1707}{500} \cdot \frac{2}{2}

分数を乗じる:

\frac{a}{b} \cdot \frac{c}{d} = \frac{a \cdot c}{b \cdot d}

= \frac{1707 2}{500 \cdot 2}

数を乗じる:

500 \cdot 2 = 1000

= \frac{1707 2}{1000}

= \frac{1707 2}{1000}