Import flux libraries inside tasks


I want to create a task that collects data from a bucket, do some maths and put it in another bucket.

The problem is that I need to perform a sin() function
Apparently import "math" does not seem to work inside task

This is what i have

// Task options
option task = {name: "displacement_results", every: 10s, offset: 0m}

import "math"

// Data source
    from(bucket: "telegraf")
        |> range(start: -task.every)
        |> filter(fn: (r) => r["_measurement"] == "I1")
        |> filter(fn: (r) => int(v: r.n) > 0)
        |> filter(fn: (r) => r["_field"] == "aX")

        // Data processing
        |> map(fn: (r) => ({r with n: r.n, level: -0.5 + 0.5 * float(v: r["n"])}))
        // new column with displacement calculated from angle
        |> map(fn: (r) => ({r with _value: r._value, dX: 0.5 * math.sin(x: r._value / 180.0 * 3.1415926)}))
        |> map(fn: (r) => ({r with dX: r.dX, cummulative_dX: r.dX}))
        |> to(bucket: "results")

SO, how can I import the trigonometric functions to use alongside with flux in Task?

best regards