展开 (A+(Ccos(y))+(Dcos(z))-(B*cos(x)))^2

解答

展开

(A + (C \cdot cos (y)) + (D \cdot cos (z)) - (B \cdot cos (x)))^{2}

A^{2} + C^{2} cos^{2} (y) + D^{2} cos^{2} (z) + B^{2} cos^{2} (x) + 2 A C cos (y) + 2 A D cos (z) - 2 A B cos (x) + C D cos (y) cos (z) - CB cos (y) cos (x) + C D cos (z) cos (y) - D B cos (z) cos (x) - CB cos (x) cos (y) - D B cos (x) cos (z)

求解步骤

(A + (C cos (y)) + (D cos (z)) - (B cos (x)))^{2}

化简

A + (C cos (y)) + (D cos (z)) - (B cos (x)) : A + C cos (y) + D cos (z) - B cos (x)

= (A + C cos (y) + D cos (z) - B cos (x))^{2}

使用指数法则:

a^{b + c} = a^{b} \cdot a^{c}

(A + C cos (y) + D cos (z) - B cos (x))^{2} = (A + C cos (y) + D cos (z) - B cos (x)) (A + C cos (y) + D cos (z) - B cos (x))

= (A + C cos (y) + D cos (z) - B cos (x)) (A + C cos (y) + D cos (z) - B cos (x))

打开括号

= AA + A C cos (y) + A D cos (z) + A (- B cos (x)) + C cos (y) A + C cos (y) C cos (y) + C cos (y) D cos (z) + C cos (y) (- B cos (x)) + D cos (z) A + D cos (z) C cos (y) + D cos (z) D cos (z) + D cos (z) (- B cos (x)) - B cos (x) A - B cos (x) C cos (y) - B cos (x) D cos (z) - B cos (x) (- B cos (x))

化简

AA + A C cos (y) + A D cos (z) + A (- B cos (x)) + C cos (y) A + C cos (y) C cos (y) + C cos (y) D cos (z) + C cos (y) (- B cos (x)) + D cos (z) A + D cos (z) C cos (y) + D cos (z) D cos (z) + D cos (z) (- B cos (x)) - B cos (x) A - B cos (x) C cos (y) - B cos (x) D cos (z) - B cos (x) (- B cos (x)) : A^{2} + C^{2} cos^{2} (y) + D^{2} cos^{2} (z) + B^{2} cos^{2} (x) + 2 A C cos (y) + 2 A D cos (z) - 2 A B cos (x) + C D cos (y) cos (z) - CB cos (y) cos (x) + C D cos (z) cos (y) - D B cos (z) cos (x) - CB cos (x) cos (y) - D B cos (x) cos (z)

= A^{2} + C^{2} cos^{2} (y) + D^{2} cos^{2} (z) + B^{2} cos^{2} (x) + 2 A C cos (y) + 2 A D cos (z) - 2 A B cos (x) + C D cos (y) cos (z) - CB cos (y) cos (x) + C D cos (z) cos (y) - D B cos (z) cos (x) - CB cos (x) cos (y) - D B cos (x) cos (z)

e x p an d \frac{2 x + 3}{2 ( x + 1 )}

e x p an d 2 (1, 2) + 3 (- 3, 4)^{'} + 2 (- 1, - 2)

e x p an d ln (4 x)

e x p an d (3 x + 2 y = 20,) (8 x + 4 y = 45)

e x p an d \frac{d ^{2}}{d ^{2} x} (x^{2} + y^{2} = 1)