Kuala Lumpur Trial 2025 Add Maths Paper 1, Question 8Differentiation

Solved on video in English · Form 5, Differentiation · 3:49 video

The question

(a)

Given that y = 3x² − 4x + 5. When x = 3, there is a small change in x by 2.5%. Find the corresponding small change in y.

(b)

Given that ∫₂⁸ g(x) dx = 12 and ∫₂⁸ k(x) dx = 9. Find the value of q if ∫₂⁸ [q k(x) + g(x)] dx = 20.

Step 1

Differentiate: dy/dx = 6x − 4.

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

Final answer

δy = 1.05

Where students lose marks

Watch out: a 2.5% change in x = 3 means 2.5% of 3 = 0.075, not 0.025. Also evaluate dy/dx at x = 3.

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

Final answer

q = 8/9

Where students lose marks

Watch out: q factors out of the k integral only. Then combine both integrals correctly: q(9) + 12 = 20.

Watch every step of this question solved on video (3:49), with the reason behind each step and a box that checks your own answer.

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