C language programming for sin (x) approximate value Description: use the formula to find sin (x) approximate value (precision is 10e-6). Sin (x) = x-x ^ 3 / 3! + x ^ 5 / 5-

C language programming for sin (x) approximate value Description: use the formula to find sin (x) approximate value (precision is 10e-6). Sin (x) = x-x ^ 3 / 3! + x ^ 5 / 5-

#include
#include
int main(void)
{int fun(int i);
int i;
float sum=0.0,x;
int temp=1;
scanf("%f",&x);
sum=x;
for(i=3;i

A cuboid is ACM in length, BCM in width and HCM in height. If the length and width remain unchanged, and the height increases by 7cm, the volume increases ()

7ab(cm3)

In order to increase the power factor of the power line to 100%, how much capacitance should be paralleled at both ends of the inductive load? What is the impedance property of the circuit at this time?

The impedance of inductance L is j ω L
The impedance of capacitance C is 1 / J ω C
Inductive load is inductance plus resistance, and impedance is R + J ω L
The total impedance is 1 / (1 / load impedance + 1 / capacitance impedance) = 1 / (1 / (R + J ω L) + J ω C))
When the impedance is pure resistance, the power factor is 100%, and the imaginary part of the impedance is 0, that is, C = L / (R * r + ω * ω * L * l)

The number of sets a satisfying {a, B} &; a ≠ &; {a, B, C, D, e}

c. D and E may or may not be in a
SO 2 * 2 * 2 = 8
But not all in a, 8-1 = 7

There are two points c and D on the line AB, ad = 15, bc18. AB is calculated by half of CD ab

cd=1/2ab ad=15 bc=18
ac+cd+bd=33-cd=33-1/2ab
That is ab + 1 / 2Ab = 33
ab=33*2/3=22
So the final result is ab = 22

Give an example of symmetric positive definite matrix
Third order
And explain why he is symmetric and positive definite

The simplest example: the identity matrix e = 1 000 1 000 1. The identity matrix is a symmetric positive definite matrix. The proof is also very simple. For any non-zero vector x, there is x'ex = x'x = | x | ^ 2 > 0. Only when x = 0 vector, x'ex is equal to 0, so it is a positive definite matrix

Find the function y = x + 1 / 2x-1, X belongs to the maximum and minimum of [3,5]

Because y = (x + 1) / (2x-1) = [1 / 2 (2x + 2)] = 1 / 2 [(2x-1) / (2x-1) + 3 / (2x-1)] = 1 / 2 [1 + 3 / (2x + 1)], when x = 5, the maximum value is y = 1 / 2 * (1 + 1 / 3) = 2 / 3, and when x = 3, the minimum value is y = 1 / 2 (1 + 3 / 5) = 3 / 10

Solving indefinite integral: ∫ x ^ 2 / (xsinx + cosx) ^ 2DX
I couldn't solve it for a long time,

Just tried with MATLAB, its indefinite integral can't be expressed by elementary function, it belongs to transcendental integral, so don't think about it any more
The following is the operation result of Mathlab:
>> F=int('x^2/(x*sin(x)+cos(x))^2')
F1=simplify(F)\x0b
pretty(F1)
Warning: explicit integral could not be found

If a number is multiplied by 11 and 9 respectively, the sum of the products is 1000

50!11+9=20 1000/20=50

Xiao Wang uses 50 yuan to buy 40 fruits for five friends. There are three kinds of fruits: apples, pears and apricots. The prices of each fruit are 200 points, 80 points and 30 points respectively. Xiao Wang hopes that he and his five friends can get apples, and the number of apples they get is different from each other. Can he realize his wish?

Let apple, pear and apricot buy x, y and Z respectively, then 200X + 80y + 30z = 5000x + y + Z = 40, eliminate Z to get 17x + 5Y = 380, so x = 380 − 5y17, because 0 ＜ y ＜ 40, so 101017 ＜ x ＜ 22617, when x = 15, y = 25, z = 0, which is not the problem