Porisma

Original question & working

Keep every absolute value in a logarithmic inequality · source reference

No exam attribution printed with this question · Question pp. 5 · Working pp. 15

Open the interactive lesson

The working and teaching notes are included in the interactive lesson.

View source review notes
Full original question, working & notes

Printed question

Sketch the graphs of y=ln⁡(1−∣x∣)y=\ln(1-|x|) and y=−∣x−1∣y=-|x-1| on the same diagram, showing clearly the equations of any asymptotes and any intersections with the axes.

Hence, solve the inequality ln⁡(1−∣x∣)+∣x−1∣≤0\ln(1-|x|)+|x-1|\le0.

Printed working

y=ln⁡(1−∣x∣)y=\ln(1-|x|).

Asymptotes: 1−∣x∣=0⇒∣x∣=1∴x=−1,x=11-|x|=0\Rightarrow|x|=1\therefore x=-1,x=1.

From GC, the curves intersect at x=−0.841x=-0.841 and x=0.433x=0.433.

ln⁡(1−∣x∣)+∣x−1∣≤0\ln(1-|x|)+|x-1|\le0.

⇒ln⁡(1−∣x∣)≤−∣x−1∣\Rightarrow\ln(1-|x|)\le-|x-1|.

⇒−1<x≤−0.841\Rightarrow-1<x\le-0.841 or 0.433≤x<10.433\le x<1.

Native source reconstruction, question 10 diagram solution

Printed answer key

Native graph above; −1<x≤−0.841 or 0.433≤x<1.

Source provenance

2025 TJC H2 Math (9758) JC2 MSM: GRAPHS AND CURVE SKETCHING. Question/answer booklet printed pages 1–14; solutions printed pages 1–28. Running metadata and repeated headings are transcribed in the topic metadata article.