Qns 1, 2, 3 were easy enough.
Qn 4c was weird? I didn't know that differential equations were in the syllabus. Got parts i), ii). Blanked on part iii).
Qn 5ciii) I didn't get during the exam, but was explained to me later - needed similar triangles...
Qn 6 HOLY SHIT the mechanics was hard...
Personally, the trigonometric applications of complex numbers are the worst for me, closely followed by inequalities and circle geometry in Harder Extension 1. I don't find the induction or probability in Harder Ext. 1 overly hard though...
Volumes, polynomials, curve sketching and...