展开 (0,0,-1)*(y,x,x-1)

解答

展开

(0, 0, - 1) \cdot (y, x, x - 1)

0, 0, y, x, x - 0, 0, 1 - 1 \cdot y, x, x + 1 \cdot 1

求解步骤

(0, 0, - 1) (y, x, x - 1)

= (0 \cdot 0,, - 1) (,, y xx - 1)

使用 FOIL 方法:

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

a = 0, 0,, b = - 1, c = y, x, x, d = - 1

= 0, 0, y, x, x + 0, 0, (- 1) + (- 1) y, x, x + (- 1) (- 1)

使用加减运算法则

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

= 0, 0, y, x, x - 0, 0, 1 - 1 \cdot y, x, x + 1 \cdot 1

e x p an d \frac{1024 l ( c - 2 t - a ) ^{2}}{405 π d ^{4}}

s im pl i f y \frac{1}{3} (x - 2) (x + 2)

e x p an d (3 x^{2} y + 2 x y + y^{3}) + (x^{2} + y^{2}) y^{'} (x)

\frac{d ^{2}}{d t ^{2}} ((x) (cos (2 t) + sin (2 t) + \frac{1}{5} e^{t}))

e x p an d - 3 (x - \frac{π}{3})