>>883
これでいいのか？
#include <stdio.h>
int main(void){
double qxxr[]= {
40.800000
,41.600000
,0.000000
,0.000000
,40.000000
,0.000000
,0.000000
,40.000000
,0.000000
,0.000000
};
double qxr;
int maa,qxxxr;

for( maa=1 , qxr = qxxr[0] ; maa < 10; maa++) {
if( qxr < qxxr[maa] ) {
qxr = qxxr[maa];
qxxxr = maa;
}
}
printf("最大のq*rは%dのとき%f¥n",qxxxr,qxr);
return 0;
}

実行結果：最大のq*rは1のとき41.600000