Skill: functions

Functions Tutor

Stuck on f(x) notation, domain, or composition? Show your input and your steps — a tutor will debug the machine with you.

1 Try self-help first

Most stuck moments are one of these. Each one links straight to the worked part of the lesson.

Re-read the worked examples

Find an example that matches your problem shape and copy its steps line by line with your own numbers.

Go to worked examples

Check the common mistakes

Compare your work against the classic wrong-vs-right pairs — the error is usually one of these three.

Go to common mistakes

Use the calculator with steps

Type your exact problem into the tool and study the step-by-step working to find where you diverged.

Open the tool

2 Ask a tutor

Still stuck? Send a help request. A tutor will reply with the first step — not just the answer — so you can finish it yourself.

Demo form: this page is a design demo. The form below does not send your request anywhere — there is no backend connected yet. Submitting shows you a preview of what your request would look like.

Your name

Please enter your name.

Email (optional)

If you include an email, that is where the tutor’s reply goes. No email, no reply — it is that simple.

What topic is this about? (optional)

What are you stuck on?

Include the actual problem and the exact step where you get lost.

Please describe what you are stuck on.

What have you tried so far?

Show your work so far — even a wrong attempt helps the tutor see where things went off track.</div>
<div class="ferror">Please tell us what you have tried so far.</div>
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<h3>What happens next</h3>
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<li><span class="n">1</span><span>A tutor reviews your question and the work you have already tried.</span></li>
<li><span class="n">2</span><span>You get a reply by email that walks you through the <em>first step</em> — not just the answer — so you can finish the problem yourself.</span></li>
<li><span class="n">3</span><span>Response time is an estimate: usually within 1–2 days. It may take longer during busy periods.</span></li>
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<p><script></p>
<p>(function(){
  var form = document.getElementById('tutor-form');
  var confirmBox = document.getElementById('confirm');
  var summaryList = document.getElementById('summary-list');
  function esc(s){
    return String(s).replace(/[&<>"']/g, function(c){
      return {'&':'&','<':'<','>':'>','"':'"',"'":'''}[c];
    });
  }
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    var okStuck = setValid('stuck', val('stuck').length > 0);
    var okTried = setValid('tried', val('tried').length > 0);
    var email = val('email');
    var emailOk = email === '' || /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email);
    setValid('email', emailOk);
    if (!okName || !okStuck || !okTried || !emailOk) return;
    var rows = [
      ['Name', val('name')],
      ['Email', email === '' ? '(none given)' : email],
      ['Topic', val('topic') === '' ? '(none chosen)' : val('topic')],
      ['Stuck on', val('stuck')],
      ['Tried so far', val('tried')]
    ];
    summaryList.innerHTML = rows.map(function(r){
      return '</p>
<dt>' + esc(r[0]) + '</dt>
<dd>' + esc(r[1]) + '</dd>
<p>';
    }).join('');
    form.style.display = 'none';
    confirmBox.classList.add('show');
    confirmBox.scrollIntoView({behavior:'smooth', block:'start'});
  });
  ['name','stuck','tried'].forEach(function(id){
    document.getElementById(id).addEventListener('input', function(){ setValid(id, true); });
  });
})();</p>
<p></script></p>
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