因式分解 1-4sin^2(x)

解答

因式分解

1 - 4 sin^{2} (x)

(1 + 2 sin (x)) (1 - 2 sin (x))

求解步骤

1 - 4 sin^{2} (x)

1 = 1^{2}

4 sin^{2} (x) = (2 sin (x))^{2}

= 1^{2} - (2 sin (x))^{2}

使用平方差公式:

x^{2} - y^{2} = (x + y) (x - y)

1^{2} - (2 sin (x))^{2} = (1 + 2 sin (x)) (1 - 2 sin (x))

= (1 + 2 sin (x)) (1 - 2 sin (x))

s im pl i f y \frac{1}{- 1 ^{2}}

s im pl i f y \frac{2}{7 + 5}

s im pl i f y 8 + \frac{8}{3}

\frac{2}{3} \div \frac{4}{9}

s im pl i f y 3 a + 4 a