Hello, I am currently working on the inverse kinematics for my scara robot. This is the code and equation I use:

```
const double L1 = 202.25;
const double L2 = 193.35;
float alpha = 0;
float beta = 0;
void calc_IK(float x, float y){
beta = acos((pow(x, 2)+pow(y, 2)-pow(L1, 2)-pow(L2, 2))/(2*pow(L1, 2)*pow(L2, 2)));
alpha = atan((y/x)-atan((L2*sin(beta))/(L1+L2*cos(beta))));
Serial.print("Beta: ");
Serial.print(beta);
Serial.print(" ");
Serial.print("Alpha: ");
Serial.print(alpha);
Serial.println(" ");
}
void setup() {
Serial.begin(9600);
}
void loop() {
calc_IK(3.0, 5.0);
delay(500);
}
```

The equation itself works on paper but the code doesn't. I get for beta 1.57 and for alpha 0.73 instead of 89° and -88°. What am I missing?