展开 (2sin(x)-sqrt(3))(12cos^2(x)-6=0)

解答

展开

(2 sin (x) - 3) (12 cos^{2} (x) - 6 = 0)

24 cos^{2} (x) sin (x) - 12 sin (x) = 0

求解步骤

(2 sin (x) - 3) (12 cos^{2} (x) - 6 = 0)

= (2 sin (x) - 3) (12 cos^{2} (x) - 6 \cdot 0 =)

使用 FOIL 方法:

(a + b) (c + d) = a c + a d + b c + b d

a = 2 sin (x), b = - 3, c = 12 cos^{2} (x), d = - 6 = 0

= 2 sin (x) \cdot 12 cos^{2} (x) + 2 sin (x) (- 6 = 0) + (- 3) \cdot 12 cos^{2} (x) + (- 3) (- 6 = 0)

使用加减运算法则

+ (- a) = - a, (- a) (- b) = ab

2 \cdot 12 sin (x) cos^{2} (x) - 2 \cdot 6 sin (x) = 0 - 123 cos^{2} (x) + 63 = 0

乘开

2 \cdot 12 sin (x) cos^{2} (x) - 2 \cdot 6 sin (x) : 24 cos^{2} (x) sin (x) - 12 sin (x)

24 cos^{2} (x) sin (x) - 12 sin (x) = 0

e x p an d \frac{x + 8}{( x - 2 ) ( x + 1 ) ( x + 2 )}

e x p an d lo g_{10} (3 \frac{3 x ^{4}}{2 y ^{5}})

e x p an d \frac{x ^{2} + 6 x + 8}{( x + 3 ) ^{2}}

e x p an d \frac{1}{a _{1} ( a _{1} + d )}

e x p an d - \frac{( s - 4 )}{( s + 1 ) ( s ^{2} + 4 )}