Write a program that calculates the distance between two points (Please help me edit)

[Kevin15663]

Write your question here.

#include <stdio.h>
#include <math.h>
int main()

{
	float x1; 
	float y1; 
	float x2; 
	float y2; 
	float Distance;
	x1 = 7;
	y1 = 12;
	x2 = 3;
	y2 = 9;
	Distance = sqrt(pow((x1-x2),2)+pow((y1-y2),2));
	printf("The distance between points (7,12) and (3,9) is f%", Distance);
	
	return 0;
	
}

I have to have this output
The distance between points (7,12) and (3,9) is 5.000000

This is what I got
The distance between points (7,12) and (3,9) is f


*I just realized this program made no sense. Not for the X and Y anyway. The formula works. I just can't get the right output.

Here is my exact problem:
Write, compile, and execute a C program that calculates the distance between two points whose coordinates are (7,12) and (3,9). Use the fact that the distance between two points having coordinates (x1,y1) and (x2,y2) is distance = sqrt([x1-x2]^2 + [y1-y2]^2).

[Danny Toledo]

Format specifiers are %(d|f|s|etc..), not (d|f|s|etc..)%

Also, your formula is a little mixed up: d² = (x2 - x1)² + (y2 - y1)²

Distance = sqrt(pow((x2-x1),2)+pow((y2-y1),2));
printf("The distance between points (7,12) and (3,9) is %f", Distance);

Hope that helps.

[Kevin15663]

Thanks Danny, simple mistake on the %f. I had a brain fart. I would have sat here all night being upset about why my program doesnt work.

[TheIdeasMan]

@Kevin

The pow function is expensive for squaring numbers because it uses a series expansion. So create 2 new variables DeltaX and DeltaY say, then just multiply them:

Distance = sqrt(DeltaX * DeltaX + DeltaY * DeltaY ) ;

Also, prefer to use double rather than float. Float has 7 or 8 significant figures of precision and this is easily exceeded, while double has 15 or 16 so it is suitable for most things.

Cheers

[Kevin15663]

@IdeaMan, I'll keep that in mind! I'm currently working on my last program. I'm sure it'll mess up and I'll have to come back and rely on y'all once more!