Design Differential Op Amp Calculator VCPlus Ep6

private: System::Void Button1_Click(System::Object^ sender, System::EventArgs^ e) {
double R3, R1, V2, V1, Av;

R1 = (float)Convert::ToDouble(textBox2->Text);   //R1 in Ohm
R3 = (float)Convert::ToDouble(textBox1->Text);   //R3 in Ohm
V2 = (float)Convert::ToDouble(textBox4->Text);   //V2 in miliVolt
V1 = (float)Convert::ToDouble(textBox3->Text);   //V1 in miliVolt
Av = (R3 / R1) * (V2 - V1); //Av=(Rf/R3)*(V2-V1)
label12->Text = Av.ToString();

}

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