SPM 2022 Add Maths Paper 1, Question 1Functions

Solved on video in English and Bahasa Melayu · Form 4, Functions · 3:00 video

The question

(a)

Diagram 1 shows the mapping of function f, x → 3p/(6 − x), such that p is a constant. (a) State the object which has no image.

(b)

Using the same function f: x → 3p/(6 − x) and the mapping in Diagram 1 (the object 2 maps to the image 9), (b) find the value of p.

Step 1

The function f(x) = 3p/(6 − x) is undefined (has no image) when the denominator is zero.

Why this step

You can't divide by zero, so an object has no image exactly when the bottom of the fraction, 6 − x, becomes 0.

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

Final answer

x = 6

Where students lose marks

Watch out: state the object as x = 6, not the inequality x ≠ 6 or 6 − x ≠ 0.

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

Final answer

p = 12

Where students lose marks

Watch out: show the substitution x = 2 into f(x) before solving for p, or you lose the working mark.

Watch every step of this question solved on video (3:00), 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.