We should respond to "reading into the family", read more, accumulate more

We should respond to "reading into the family", read more, accumulate more

We should respond to the call of "reading into the family", read more and accumulate more

In response to the activity of "reading into thousands of homes", we should read more and accumulate more

In response to the call of "reading into thousands", we should read more and accumulate more
Respond to The call is a common sentence, so add the three words in brackets above

In the cube abcd-a'b'c'd ', it is proved that the diagonal b'd is perpendicular to the plane a'c'b

Connecting B ′ C, there is B ′ C ⊥ BC ′
The BCC ′ B ′ of DC ⊥ plane has BC ⊥ plane B ′ DC
Similarly, BA ′⊥ plane B ′ DC, C ′⊥ a ′⊥ plane B ′ DC
Plane B ′ DC ⊥ plane a ′ BC ′
Ψ B ′ D ⊥ plane a ′ BC ′

Matlab calculation of polynomial multiplication?
If f (x) = 2 + 3 * x ^ - 1 and f (x) = 2 * x + 3 * x ^ - 1 + 4 * x ^ - 2 are multiplied, how can we write them in MATLAB,

The symbolic operation function of MATLAB is used
syms x fx1 fx2 fx3
fx1=2+3*x^(-1)
fx2=2*x+3*x^(-1)+4*x^(-1)
fx3=fx1*fx2

It is known that the length of the wiper is 40cm, and the center angle of the wiper swing is 135 degrees, then the arc length of the wiper tip is 135 degrees______ cm．

3.14 × 2 × 40 △ 360 °× 135 ° = 251.2 △ 360 °× 135 °, = 94.2 (CM), answer: the arc length of the wiper tip is 94.2 cm, so the answer is: 94.2

Sum of equal ratio sequence: 1 / 2,3 / 2 ^ 2,5 / 2 ^ 3,7 / 2 ^ 4 ,(2n-1)/2^n,

S=1/2+3/2^2+...+(2n-1)/2^n
S/2=1/2^2+.+(2n-3)/2^n+(2n-1)/2^(n+1)
Subtraction:
S/2=1/2+2*(1/2^2+1/2^3+...+1/2^n)-(2n-1)/2^(n+1)
=1/2+1/2+1/2^2+...+1/2^(n-1)-(2n-1)/2^(n+1)
=1/2+1/2*[1-1/2^(n-1)]/(1-1/2)-(2n-1)/2^(n+1)
=1/2+1-1/2^(n-1)-(2n-1)/2^(n+1)
=3/2-(2n+3)/2^(n+1)
S=3-(2n+3)/2^n

Binary linear equation solution and substitution elimination method and addition and subtraction elimination method? How to solve the problem

Substituting elimination is to use one quantity in another table, and then substitute it into the equation you haven't used before. In this way, it becomes one variable once
Addition and subtraction is that you make the absolute value of the coefficient of an unknown number in two equations equal by multiplying and dividing the coefficients on both sides of the equation, and then add and subtract the two equations to eliminate one element

What deeds of Deng Jiaxian reflect the character's character

Deng Jiaxian is an outstanding representative of Chinese intellectuals. For the sake of the prosperity of the motherland and the development of national defense scientific research, he is willing to be an unknown hero and has struggled for decades in obscurity

What is the power of X to the power of 3, y to the power of 2 × (- 2x to the power of 3, y to the power of 3)?

Hello
The third power of X, the second power of Y × (- the third power of 2x, the third power of Y)
=The third power of X, the second power of Y × (the sixth power of 4x, the sixth power of Y)
=4X to the 9th power and y to the 8th power
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Solving equation 30% x = 90
Formula calculation

X＝90÷30％
X＝90*100/30＝300