Terms and Conditions

These Terms and Conditions ("Terms") govern your use of the CalculusDX website and online course (the "Service"). By creating an account or using the Service, you agree to these Terms and to our Privacy Policy.

1. Eligibility

You must be at least 13 years old to use the Service. If you are under the age of majority where you live, you may use the Service only with the permission of a parent or guardian, who agrees to these Terms on your behalf.

2. Your account

You sign in using a link sent to your email. Keep access to your email secure; you are responsible for activity on your account. Give us an accurate email address and tell us if you believe your account has been misused.

3. Course access

The course is free. You must create an account to access the course.

4. Acceptable use

You agree not to:

• copy, resell, redistribute, or republish course content without our written permission;
• share your account or sign-in links with others;
• scrape, overload, or interfere with the Service or attempt to access it without authorization;
• use the Service for any unlawful purpose.

5. Intellectual property

All course content, including lessons, problems, solutions, graphs, and branding, belongs to CalculusDX or its licensors. We grant you a personal, non-transferable, revocable license to use it for your own learning.

6. Educational purpose only

The Service is a self-paced study resource. It is not an accredited course and does not grant academic credit. We do not guarantee any particular grade, exam score, or outcome.

7. Communications

We will send you emails needed to run the Service, such as sign-in links and important account notices. Marketing emails (newsletters, offers, new courses) are sent only if you opt in, and you can unsubscribe at any time.

8. Disclaimers

The Service is provided "as is" and "as available". We work hard to keep content accurate, but we do not warrant that it is error-free or that the Service will be uninterrupted.

9. Limitation of liability

To the fullest extent permitted by law, CalculusDX is not liable for any indirect, incidental, or consequential damages arising from your use of the Service. Nothing in these Terms limits rights you have under consumer protection laws that cannot be waived.

10. Ending your use

You may stop using the Service and delete your account at any time from your account page. We may suspend or close accounts that break these Terms.

11. Changes to these Terms

We may update these Terms. If changes are significant, we will notify you by email or on the site. Continuing to use the Service after changes take effect means you accept the updated Terms.