SPM 2018 Add Maths Paper 2, Question 1
Solved on video in English and Bahasa Melayu · 6 marks · 5:16 video
The question
The sum of the first n terms of an arithmetic progression, S_n, is given by S_n = 3n(n - 33)/2. Find (a) the sum of the first 10 terms, (b) the first term and the common difference, (c) the value of q, given that the qth term is the first positive term of the progression.
[6 marks]
5:16Step 1
Substitute n = 10 into the given sum formula: S_10 = 3(10)(10 - 33)/2 = 3(10)(-23)/2 = -690/2 = -345.
5 more steps, each with the reason for it, in the full solution
Final answer
S_10 = -345; a = -48, d = 3; q = 18
Where students lose marks
Watch out: T_17 = 0 is not positive, so the first positive term is the 18th, not the 17th.
Watch every step of this question solved on video (5:16), with the reason behind each step and a box that checks your own answer.
No card. Every past-year question on video, in English and BM.
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