C++

[charlemagne03]

Hi,

Can anyone help with this with the error I am getting?

#include <iostream>
#include <cmath>
#define PI 3.1416


using namespace std;

int main()

//Q1-------------------------------------------------------------------------------------------
{
for (theta=0;theta<=21;0<theta<=2PI)

double theta;
double sin<theta>;
double cos<theta>;
double tan<theta>;




cout << ""<<sin << endl;
return 0;
}

[TX9200]

I think you dont quite get the feel of it.
(1)double theta needs to be declared first before or in for iteration

(2) 0<theta<=2PI is a bad expression. Use
0<theta && theta<=2PI

(3)Paramenter bound uses "()" not "<>"

(4) your for loop will only loop the next statement if you do not use "{}" to wrap around;

[giblit]

Can you explain what you are trying to do Charle?

Also sin/cos/tan are functions so you can't name variables that or it will more than likely have naming conflicts. Also even if you did declare theta before the for loop it would be an endless loop because you never increment it.


Once again if we had a formula or what exactly you are trying to do we could be of more help.

[charlemagne03]

Giblit,

I am attempting write a program that uses a for loop to compute and output Sin(0), Cos(0), Tan(0) for 21 values of 0(theta) equally spaced between 0 and 2Pi.

[giblit]

so In other words you are going from 0 -> 6.28318 over 21 iterations. So basically the for loop would look like:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

double theta; const double max = 6.28318; //estimate of 2pi const int iterations = 20; //we must iterate 20 times // after the initial 0 for a total of 21 const double threshold = 0.0000001; //threshold for comparing doubles for( theta = 0.0; theta < max + threshold; theta += max / iterations ) { std::cout << "Cos(" << theta << ") = " << cos( theta ) << std::endl; //repeat for sin and tan. }

Cos(0) = 1 Cos(0.314159) = 0.951057 Cos(0.628318) = 0.809017 Cos(0.942477) = 0.587786 Cos(1.25664) = 0.309018 Cos(1.57079) = 1.32679e-06 Cos(1.88495) = -0.309015 Cos(2.19911) = -0.587784 Cos(2.51327) = -0.809016 Cos(2.82743) = -0.951056 Cos(3.14159) = -1 Cos(3.45575) = -0.951057 Cos(3.76991) = -0.809019 Cos(4.08407) = -0.587788 Cos(4.39823) = -0.309021 Cos(4.71239) = -3.98038e-06 Cos(5.02654) = 0.309013 Cos(5.3407) = 0.587782 Cos(5.65486) = 0.809014 Cos(5.96902) = 0.951055 Cos(6.28318) = 1

http://ideone.com/4g8JHu

[charlemagne03]

theta sin(theta) cos(theta) tan(theta)
----------------------------------------------------------------------
0.000000 0,000000 1.0000000 0.00000000
0.314







how would you setup a list that end @ 20 values

[giblit]

Just modify the output on the last message I said to your format.