46 lines
1.4 KiB
C
46 lines
1.4 KiB
C
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/* Cosine Series - Program to find cos(x) using the series: cos(x) = 1 - (x^2) / 2! + (x^4) / 4! - (x^6) / 6! + .... Do calculations till the value of the next term is not lesser than 10^-5 */
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/* We assume that the angle entered by user is between 0 and 2 pi radians (0 and 360 degrees) */
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#include <stdio.h>
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#include <conio.h>
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#define pi 3.141593
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void main()
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{
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double d, x, i=0, s=0, f=1, num, nt;
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int tc=1 ;
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/* s-sum , f-factorial , num - nemerator , nt - next term , tc - term count */
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clrscr() ;
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printf("Enter the angle in degrees: ") ;
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scanf("%lf", &d) ;
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x=d*pi/180 ; /* converts angle to radians */
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num=1 ;
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while(1)
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{
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f=f*i*(i-1) ; /* Calculates factorial */
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if(f==0)
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f=1 ;
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nt=num/f ; /* calculates next term */
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if(nt<0.00001)
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break ; /* stops if next term is less than 10 raise to -5 */
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if(tc%2==1) /* alternating + and - */
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s=s+nt ; /* calculates sum*/
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else
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s=s-nt ;
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/* Preparation for next execution */
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i=i+2 ;
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tc++ ;
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num=num*x*x ;
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}
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printf("The cosine of angle %lf is %lf", d, s) ;
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getch() ;
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}
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/*
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Output
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Enter the angle in degrees: 60
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The cosine of angle 60.000000 is 0.500000
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*/
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