为什么我的数组显示为整数而不是浮点数

问题看起来像这样

https://i.imgur.com/u0LJO0g.png

我哪里出错了？

#include<stdio.h>
int main(){
    int i,n;
    int a[] = {3,5,7};
    float x[] = {0,0,0};

    printf("function f(x)=(x^3-2x^2+10x-5)/(x-10)\n");

    for(i = 0;i<3;i++){
        x[i] = (a[i]^3-2*(a[i]^2)+10*a[i]-5)/(a[i]-10);
    }

    for(n = 0;n<3;n++){
        printf("if x is %d,f(x) is %f\n",a[n],x[n]);
    }
}

我希望输出看起来像这样

if x is 3,f(x) is -5.14
if x is 5,f(x) is -24.00
if x is 7,f(x) is -103.33

但实际输出是

if x is 3,f(x) is -3.000000
if x is 5,f(x) is -7.000000
if x is 7,f(x) is -20.000000