展開する (1-0.8cos(x))^2

解

展開する

(1 - 0.8 cos (x))^{2}

1 - 1.6 cos (x) + 0.64 cos^{2} (x)

解答ステップ

(1 - 0.8 cos (x))^{2}

完全平方式を適用する:

(a - b)^{2} = a^{2} - 2 ab + b^{2}

(1 - 0.8 cos (x))^{2} = 1^{2} - 2 \cdot 1 \cdot 0.8 cos (x) + (0.8 cos (x))^{2}

= 1^{2} - 2 \cdot 1 \cdot 0.8 cos (x) + (0.8 cos (x))^{2}

簡素化

1^{2} - 2 \cdot 1 \cdot 0.8 cos (x) + (0.8 cos (x))^{2} : 1 - 1.6 cos (x) + 0.64 cos^{2} (x)

= 1 - 1.6 cos (x) + 0.64 cos^{2} (x)