Math Is Fun Forum

hey come on, zach week is over...

is that the same Ricky who hangs out here?

So what about your math background? Where did you study, got any goals for the future concerning math?

Yay! I'm a tiger! Give me a giant steak or I'll eat you!

Not suprising...

Well just  wrote this program to use numerical integration of the area of a unit circle in the first quadrant, then multiply that by 4 to find pi. It works but using super large values of x seems to decrease the level of accuracy rather then increase it. Probably 'cause the values aren't being stored to enough decimal places and loosing their accuracy.

#include <iostream>
#include <math.h>

float f(float x);

int main()
{

float x;

float n = 200000;

for (int i = 0; i < n; i++)
{

 x += 1/n * f(i/n);

}


std::cout << "pi = " << 4 * x << "\n";

return 0;

}




float f(float x)
{

if ((1 - x*x) < 0) { std::cout << "error " << x << "\n"; return 0; }

return sqrt(1 - x*x);

}

What the heck is gradients? Oddly my mathbook never mentioned that term.

What exactly are we trying to find here? All I see is desription, no question.

Yeah, just had to multiply above and below by cos x and we would have had it.

Wish I could ask my dad for help. He went as far as calculus 2 in college but never really had to use it, so he forgot most of it. What a pity...

What about girls who are bad at maths? What do they get to help them pay attention?

Put a dollar sign in front of every number. That should do the trick.

ricky is right. Thats the same thing I read. Like I said, by convention,  √x means the positive square root. Where as if you were to verbally ask for the square root, it could mean the positive or negative root.

But of course, if you have the expression x^2 = 4, you can take the square root of both sides but you must consider the postive and negative square root. x = +- √4     note! If √4 represented the positive AND negative square root of 4, then the +- signs would be uneccessary and redundant.