Please help me with summation in C lang. I m trying to divide the summation of alpha * delta with summation of alpha this is half the program that i have written...but it gives error. pls help.. This is my program, it says invalid indirection in function main ] i haved use stdio.h and math.h main () { float del1, del2,deli,delj,deln, alpha; int j,vi,i; int sum=0; printf ("provide alpha"); scanf ....... for (j=1;j<=vi;j++) sum += alpha [i][j] *deln [j]; } Please help me with summation in C lang. I m trying to divide the summation of alpha * delta with summation of alpha this is half the program that i have written...but it gives error. pls help..

sum += alpha [i][j] *deln [j]; How do you expect the compiler to treat alpha and deln as arrays if you haven't declared them as such?