展开 (6+2cos(θ))^2

解答

展开

(6 + 2 cos (θ))^{2}

36 + 24 cos (θ) + 4 cos^{2} (θ)

求解步骤

(6 + 2 cos (θ))^{2}

使用完全平方公式:

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

(6 + 2 cos (θ))^{2} = 6^{2} + 2 \cdot 6 \cdot 2 cos (θ) + (2 cos (θ))^{2}

= 6^{2} + 2 \cdot 6 \cdot 2 cos (θ) + (2 cos (θ))^{2}

化简

6^{2} + 2 \cdot 6 \cdot 2 cos (θ) + (2 cos (θ))^{2} : 36 + 24 cos (θ) + 4 cos^{2} (θ)

= 36 + 24 cos (θ) + 4 cos^{2} (θ)

e x p an d 2 (1 + ln (2))

e x p an d \frac{6}{( x - 1 ) ^{4}}

e x p an d (- t sin (t) + cos (t))^{2}

e x p an d (5 x^{2} - 10)^{3} x d x

s im pl i f y (x - \frac{1}{3}) (x + \frac{1}{3})