```calc
x := 1
root(x^3 - 2*x - 5, x) = ?
root(cos(x) - x, x, 0, 1) = ?
```

```calc
polyroots([-6; 11; -6; 1]) = ?
polyroots([1; 0; 1]) = ?
```

```calc
a := 1 m
b := 4 m
given
a + b == 5 m
a*b == 6 m^2
find(a, b) = ?
```

```calc
x_d := [1; 2; 3; 4]
y_d := [2.1; 3.9; 6.2; 7.8]
a := 1
b := 0
given
a*x_d[0] + b == y_d[0]
a*x_d[1] + b == y_d[1]
a*x_d[2] + b == y_d[2]
a*x_d[3] + b == y_d[3]
minerr(a, b) = ?
```