The keyword "updated" is critical. The SQA Higher Mathematics course underwent significant changes in the last decade, moving from the old Higher (pre-2015) to the new CfE Higher (2015 onwards).
When searching for a PDF, you must ensure you get the Updated Edition (often called the New Edition or CfE Edition). Here is what the update includes: teejay higher maths textbook pdf updated
If the cost is a barrier:
You will see many results on Reddit, Discord servers, or file-sharing sites claiming to have the "Updated TeeJay Higher Maths PDF." The keyword "updated" is critical
Proceed with extreme caution.