第七周 项目二 并联电阻

</pre><pre class="cpp" name="code">#include <iostream>using namespace std;int main() {   double r,r1,r2;     cout<<"输入两个电阻r1与r2的阻值";     cin >>r1 >>r2;     r=1/(1/r1+1/r2);    cout << "并联后的阻值为:" << r<<endl;    return 0; }