SPM 2017 Add Maths Paper 1, Question 6Indices, Surds & Logarithms

Solved on video in English and Bahasa Melayu · 3 marks · Form 4, Indices, Surds & Logarithms · 5:43 video

The question

Solve the equation: log_m 324 - log_(sqrt m) 2m = 2.

[3 marks]

Step 1

Change the base of the second term to base m: log_(sqrt m) 2m = log_m(2m) / log_m(sqrt m) = log_m(2m) / (1/2) = 2 log_m(2m) = log_m (2m)².

Why this step

Logs only combine when they share a base, so we switch to base m. Since log_m √m = ½, dividing by it just doubles.

5 more steps, each with the reason for it, in the full solution

Final answer

m = 3

Where students lose marks

Watch out: reject m = −3, because a log's base must be positive. Also take care with the change of base.

Watch every step of this question solved on video (5:43), 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.

Questions are re-typeset by Eduly for study and commentary. Eduly is not affiliated with Lembaga Peperiksaan Malaysia or the Ministry of Education.