Thread: exponents are LAAAME

I'm having trouble writing exponents. I know initially how you're supposed to define a variable and use the pow() func. but my scenario is a bit different and I need to compile and email this by tonight


x = pow(4,6);
something like this, where it's showing 4 to the 6th power. as i said before, my case is a little worse.
when I (try to) compile it, it says "invalid operands to binary ^" then there's a whole LIST of all the variables I put in. "invalid suffix "z" on integer constant
"invalid suffix "x" onasaifasfjaklsjgkasjg.. and so on.

Code:

#include <stdio.h>
#include <math.h>

main()
{
int p1;
int p2;
int p3;
int p4;
int p5;
	printf("Directions:\n");
	printf("Simplify the monomials.\n");
	printf("Write out exponents using the "^" key.\n");
	printf("12p^5 = 12 times p to the 5th power\n"); /* this is a thing I did for my math teacher for extra credit basically*/


/*--------------------------------------------------------*/
	printf("54x^3z, 36z^5x\n");
	scanf("&#37;d", &p1);
if (p1 != 18z)
{ printf("Incorrect\n"); }
else
{ printf("Correct\n"); }
system("pause");
/*-----------------------------------------------------*/
	printf("74ac, 116b^3a\n");
	scanf("%d", &p2);
if (p2 != 2a)
{ printf("Incorrect\n\a"); }
else 
{ printf("Correct\n"); }
system("pause");
/*------------------------------------------------------*/

	printf("2xyz^4t^3, 14pz^2y^5\n");
	scanf("%d", &p3);
if (p3 != 2z^2y)
{ printf("Incorrect\n"); }
else
{ printf("Correct\n");}
system("pause");
/*---------------------------------------------------------*/
	printf("6y^4, 12y^2\n"); 
	scanf("%d", &p4);
if (p4 != 6y^2)
{ printf("incorrect\n\a"); }
else
{ printf("correct\n"); }
system("pause");
/*-------------------------------------------------*/
	printf("8mp^3, 20x^7p^5\n");
	scanf("%d", &p5);
if (p5 != 4p^3)
{ printf("Incorrect\a\n"); }
else
{ printf("Correct\n"); }

	printf("Thank you for playing!\n");

system("pause");

return 0;
}

And you believe that 18z is an integer, as opposed to oh, say, a string, because why?

(Also the common factor -- if that's what you're doing -- of the first pair is 18xz.)

you are forgettign that you have to explicitly code the multiplication operator, 2z isnt 2 times z its an invlid variable, you have to code 2 * z instead, and remember the order fo operations so enclose (2*z)^(2*y). Also remember than in C/C++ the ^ operator is bitwise XOR not exponent. So what you really want is pow(2 * x , 2 * y);

so you're saying for every "variable" that is an invalid variable (2x) I have to write out as pow(2*x);? or something similar

Between abachler and myself, one of us is completely horrendously wrong. I'm betting it's not me, but I would anyway. My guess is that you want the user to literally type "2z^2y" or "2yz^2" as the answer to the problem, which you would then need to compare (as a string, not an integer, naturally) to the right answer hardcoded in (which would also need to be a string, not an integer, naturally).

so I wouldn't define it as 'int', but as 'char'

Originally Posted by Sm33zy

so I wouldn't define it as 'int', but as 'char'

Closer; you need a whole bunch of chars. A char array, perhaps.

Of course, you will need to make this change throughout.

it came down to this. This is a different copy from my original file so I screwed around with it a bit. I'm sure it's obviously still full of errors so I think I'll just call it a night

Code:

#include <stdio.h>
#include <math.h>

main()
{
int p1= 18*2;
int p2=2*4;
int p3=2*z*z*y;
int p4=6*y*y;
int p5=4*p*p;
	printf("Directions:\n");
	printf("Simplify the monomials.\n");
	printf("I believe the ^ key is invalid in C\n");
	printf("plz write out your answer using parentheses.\n");
	printf("ex. 2*x instead of 2x because 2x is an invalid variable here.\n");

/*--------------------------------------------------------*/
int x;
int y;
int z;
	printf("54*x*y*2, 36*z*5*x\n");
	scanf("%d/%d/%d",&x,&y,&z);
if (p1 != 18*z)
{ printf("Incorrect\n"); }
else
{ printf("Correct\n"); }
system("pause");
/*-----------------------------------------------------*/
int a[2];
int c;
int b;

	printf("74*a*c, 116*b*3*a\n");
	scanf("%d/%d/%d",&a,&b,&c);
if (p2 != 2*4)
{ printf("Incorrect\n\a"); }
else 
{ printf("Correct\n"); }
system("pause");
/*------------------------------------------------------*/
int x[2];
int y[2];
int z[2];
int t;
	printf("2*x*y*z*4*t*3, 14*x*z*2*y*5\n");
	scanf("%d/%d/%d", &x,&z,&y);
if (p3 != 2*z*z*y)
{ printf("Incorrect\n"); }
else
{ printf("Correct\n");}
system("pause");
/*---------------------------------------------------------*/
int y;
	printf("6*y*2, 12*y*2\n"); 
	scanf("%d", &y);
if (p4 != 6*y*y)
{ printf("incorrect\n\a"); }
else
{ printf("correct\n"); }
system("pause");
/*-------------------------------------------------*/
int m;
int p;
int x;
int p;
	printf("8*m*p*3, 20*x*7*p*5\n");
	scanf("%d/%d/%d", &m,&p,&x);
if (p5 != 4*p*p)
{ printf("Incorrect\a\n"); }
else
{ printf("Correct\n"); }

	printf("Thank you for playing!\n");

system("pause");

return 0;
}