Thread: Beginner at C! help...Array problem

'using a for loop, construct two 100 element arrays, x,y such that i of x stores the value sin(2*pi*i/100) and corresponding for y cos(''' ')print the values stored in elements of x,y as you calculate..'

cant see where im wrong?

Many thanks!!!!

insert

Code:

#include <stdio.h> 
#include <stlib.h> 
#define PI 3.142



int main()

{
//stating variable type and titles of the arrays

int i, x[100], y[100]; 

   for(i=0; i<=100; i++)
  
   x[i]=sin((2*PI*i)/100)); //in general for every element
   y[i]=cos((2*PI*i)/100));
   
   printf("%.2f\t %.2f\n",x[i],y[i]);
   

   scanf("d\n");
   
   exit(0);
   }

Thanks!!!!! your the master.

why must x y be floats of doubles?

why not floats of floats?

Np

you need to use a float or double to store numbers with fractions. Either will do but doubles give better precision. Sin and cos return numbers between -1 and 1 so using integers all numbers would end up being -1, 0, or 1.

Also, technically, not that it matters too much here, but sin is meant to be for y, and cos for x.

Okay..thanks!

This question develops: "compute the dot products of x.x,, y.y, x.y checking that sinx and cosx are orthogonal..x.y=sum(x.y) "

I am really stuck here. Maybe that is my maths. My attempt is as pitifully follows:

include

Code:

#include <stdio.h> 
#include <stlib.h> 
#define PI 3.142

int main()

{
//stating variable type and titles of the arrays
int i;
float ,sinC, x[36], y[36], sumsq, sumsr, sumss;

   for(i=0; i<=360; i++)
  {
   
   
   x[i]*y[i]= sin
   y[i]*y[i]=  
  
   //shall i define the arrays? or the mulitiplied arrays?  
   
   x.y=absinc?
  
  
   sumsq=x[i]*x[i]
   sumsr=y[i]*y[i] 
   sumss=x[i]*y[i]
   
   
   
   
   
   printf("&#37;.2f\t %.2f% %.2f\n",sumq, sumsr, sumss);
   }

   scanf("d\n");
   
   exit(0);
   }