I Got an N determination warning in maths standard grade 11 for an assingment. Will this ruin my hsc?
its just a warning but make sure you be more attentive to assignment dates in the future since N awards can prohibit you entry into Year 12 however that is very unlikely if you are a someone who at least meets the minimum expectations for the course.
Your prelims don't affect your HSC but how you set yourself up in prelims will influence in how the HSC year is but not determine it (of course you can always turn around, there's countless stories of people expected to underperform but hitting high atars). Good habits build over time so try to use a system such as a calendar or alarm to ensure you don't do it again.
Know a guy in Year 12 who didn't take prelims seriously and had to go through the pain of administration and catching up on N awards etc... he ended up dropping by his/her own accord.