func Cos(_ context.Context, args ...core.Value) (core.Value, error) {
	err := core.ValidateArgs(args, 1, 1)
	if err != nil {
		return values.None, err
	}
	err = core.ValidateType(args[0], types.Int, types.Float)
	if err != nil {
		return values.None, err
	}
	return values.NewFloat(math.Cos(toFloat(args[0]))), nil
}
Cos returns the cosine of a given number.
@param number (Int|Float) - Input number.
@returns (Float) - The cosine of a given number.
package math
import (
	"context"
	"math"
	"github.com/MontFerret/ferret/pkg/runtime/core"
	"github.com/MontFerret/ferret/pkg/runtime/values"
	"github.com/MontFerret/ferret/pkg/runtime/values/types"
)