A student in Indonesia is about to start a Biomedical Engineering degree course at a Malaysian University.

Unfortunately, the standard of teaching in Indonesia is pathetic thanks to the corruption and nepotism prevalent here.
The student has been sent exam past papers by the uni, to help her prepare for the course.

The student didn't even know that the sum of angles in a triangle = 180, or even Pythagoras' Theorem for right-angled triangles.
I studies A-level maths from 1990 to 1992, and have managed to teach the student the basics of trig, differentiation and Integration. But, even I am struggling to answer some of the questions due to ignorance or just being rusty.
I would be grateful if you guys could answer the questions on the past-paper so that I can help this student. I am prepared to contribute whatever I can towards the solutions.
There are about 4 past papers. I have attached one below.