cos(x)=-1/6

解

cos (x) = - \frac{1}{6}

x = 1.73824 \dots + 2 πn, x = - 1.73824 \dots + 2 πn

度

x = 99.59406 \dots^{\circ} + 36 0^{\circ} n, x = - 99.59406 \dots^{\circ} + 36 0^{\circ} n

解答ステップ

cos (x) = - \frac{1}{6}

三角関数の逆数プロパティを適用する

cos (x) = - \frac{1}{6}

以下の一般解

cos (x) = - \frac{1}{6}

cos (x) = - a \Rightarrow x = arccos (- a) + 2 πn, x = - arccos (- a) + 2 πn

x = arccos (- \frac{1}{6}) + 2 πn, x = - arccos (- \frac{1}{6}) + 2 πn

x = arccos (- \frac{1}{6}) + 2 πn, x = - arccos (- \frac{1}{6}) + 2 πn

10進法形式で解を証明する

x = 1.73824 \dots + 2 πn, x = - 1.73824 \dots + 2 πn