化简 3cos^2(x)-3

解答

化简

3 cos^{2} (x) - 3

- 3 sin^{2} (x)

求解步骤

3 cos^{2} (x) - 3

使用毕达哥拉斯恒等式:

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

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

= 3 (- sin^{2} (x))

分解

3 cos^{2} (x) - 3 : 3 (cos^{2} (x) - 1)

= 3 (cos^{2} (x) - 1)

= - 3 sin^{2} (x)

s im pl i f y \frac{( 18 x ^{2} - 21 x )}{( 6 x - y )}

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

s im pl i f y (x - 2 y) + (2 y - 3 z) 3 + (3 z - x) 3

s im pl i f y \frac{2}{3} \cdot (- b + a) + b

s im pl i f y \frac{( 3 \frac{x}{5} )}{( 3 \frac{x}{4} )}