basic function

[rapid dagger]

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Markup

```cpp
int main() {}
```

Result

int main() {}

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[hollow fable]

#include <iostream>
#include <cmath>

double arct(double x) {
    return atan(x) - 1;
}
double darct(double x) {
    return 1 / (1 + x*x);
}

double poly(double x) {
    return x*3 + 2*x*2 + 10*x - 20;
}
double dpoly(double x) {
    return 3*x*x + 4*x + 10;
}

double lincos(double x) {
    return cos(x) - x;
}
double dlincos(double x) {
    return -1*sin(x) - 1;
}

double tanf(double x) {
    return tan(x) - (1 / (1 + x*x));
}
double dtanf(double x) {
    return cos(x)*(-2) + (2*x) / (1 + x*x)*2;
}