Question 7 b iii
http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2011exams/pdf_doc/2011-hsc-exam-mathematics-ext1.pdf ---exam
http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2011exams/pdf_doc/mathematics-extension-1-hsc-sample-answers-11.pdf --solutions
Can someone explain the...