展开 (1+2*sin(θ))^2

解答

展开

(1 + 2 \cdot sin (θ))^{2}

1 + 4 sin (θ) + 4 sin^{2} (θ)

求解步骤

(1 + 2 sin (θ))^{2}

使用完全平方公式:

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

(1 + 2 sin (θ))^{2} = 1^{2} + 2 \cdot 1 \cdot 2 sin (θ) + (2 sin (θ))^{2}

= 1^{2} + 2 \cdot 1 \cdot 2 sin (θ) + (2 sin (θ))^{2}

化简

1^{2} + 2 \cdot 1 \cdot 2 sin (θ) + (2 sin (θ))^{2} : 1 + 4 sin (θ) + 4 sin^{2} (θ)

= 1 + 4 sin (θ) + 4 sin^{2} (θ)

e x p an d (x + 1) (2 x + 9 = 0)

e x p an d \frac{1}{20} (x + 3)

e x p an d 4 x (\frac{6}{x} + \frac{x - 3}{4} = 2) 4 x

e x p an d 5 (11 - 6)

e x p an d 2 x (1 + y^{2}) d x - y (1 + 2 x^{2}) d y