# C Programming (Turbo / Visual C++ Compiler) - Using Sine Series to find Sin Value

I have given here a C program to find the value of sin using Sine Series and without using the library function. This program will print the values got from the series function MySin and library function sin.

sin series = x - x^3/3! + x^5/5! - x^7 / 7! + x^9 / 9! - .......

## Source Code

#include <math.h>

#include <stdio.h>

const double PI = 3.14159265;

// sin series = x - x^3/3! + x^5/5! - x^7 / 7!

double MySin(double x)

{

double sqx = x * x * x;

double sineresult = x;

double fact = 2 * 3;

int index = 3;

int term = 0;

double termfactor = 0;

for(term = 1; term < 20; term++)

{

termfactor = 0;

termfactor = sqx / fact;

if(term % 2)

{

sineresult = sineresult - termfactor;

}

else

{

sineresult = sineresult + termfactor;

}

index++;

fact *= index;

index++;

fact *= index;

sqx *= (x*x);

}

return sineresult;

}

int main()

{

double i = 0;

for(i = 0; i <= 360; i += 4.75)

{

printf("%.4lf = %.4lf\t%.4lf\n", i,

sin(i * PI / 180), MySin(i * PI / 180));

//printf("%.4lf\n", sin(i * PI / 180) - MySin(i * PI / 180));

}

return 0;

}

## Output

0.0000  = 0.0000        0.0000

4.7500  = 0.0828        0.0828

9.5000  = 0.1650        0.1650

14.2500 = 0.2462        0.2462

19.0000 = 0.3256        0.3256

23.7500 = 0.4027        0.4027

28.5000 = 0.4772        0.4772

33.2500 = 0.5483        0.5483

38.0000 = 0.6157        0.6157

42.7500 = 0.6788        0.6788

47.5000 = 0.7373        0.7373

52.2500 = 0.7907        0.7907

57.0000 = 0.8387        0.8387

61.7500 = 0.8809        0.8809

66.5000 = 0.9171        0.9171

71.2500 = 0.9469        0.9469

76.0000 = 0.9703        0.9703

80.7500 = 0.9870        0.9870

85.5000 = 0.9969        0.9969

90.2500 = 1.0000        1.0000

95.0000 = 0.9962        0.9962

99.7500 = 0.9856        0.9856

104.5000 = 0.9681       0.9681

109.2500 = 0.9441       0.9441

114.0000 = 0.9135       0.9135

118.7500 = 0.8767       0.8767

123.5000 = 0.8339       0.8339

128.2500 = 0.7853       0.7853

133.0000 = 0.7314       0.7314

137.7500 = 0.6724       0.6724

142.5000 = 0.6088       0.6088

147.2500 = 0.5410       0.5410

152.0000 = 0.4695       0.4695

156.7500 = 0.3947       0.3947

161.5000 = 0.3173       0.3173

166.2500 = 0.2377       0.2377

171.0000 = 0.1564       0.1564

175.7500 = 0.0741       0.0741

180.5000 = -0.0087      -0.0087

185.2500 = -0.0915      -0.0915

190.0000 = -0.1736      -0.1736

194.7500 = -0.2546      -0.2546

199.5000 = -0.3338      -0.3338

204.2500 = -0.4107      -0.4107

209.0000 = -0.4848      -0.4848

213.7500 = -0.5556      -0.5556

218.5000 = -0.6225      -0.6225

223.2500 = -0.6852      -0.6852

228.0000 = -0.7431      -0.7431

232.7500 = -0.7960      -0.7960

237.5000 = -0.8434      -0.8434

242.2500 = -0.8850      -0.8850

247.0000 = -0.9205      -0.9205

251.7500 = -0.9497      -0.9497

256.5000 = -0.9724      -0.9724

261.2500 = -0.9884      -0.9884

266.0000 = -0.9976      -0.9976

270.7500 = -0.9999      -0.9999

275.5000 = -0.9954      -0.9954

280.2500 = -0.9840      -0.9840

285.0000 = -0.9659      -0.9659

289.7500 = -0.9412      -0.9412

294.5000 = -0.9100      -0.9100

299.2500 = -0.8725      -0.8725

304.0000 = -0.8290      -0.8290

308.7500 = -0.7799      -0.7799

313.5000 = -0.7254      -0.7254

318.2500 = -0.6659      -0.6659

323.0000 = -0.6018      -0.6018

327.7500 = -0.5336      -0.5336

332.5000 = -0.4617      -0.4617

337.2500 = -0.3867      -0.3867

342.0000 = -0.3090      -0.3090

346.7500 = -0.2292      -0.2292

351.5000 = -0.1478      -0.1478

356.2500 = -0.0654      -0.0654
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