IGCSE Booklet 21 – Solving Quadratic Equations | Original 22-page PDF

Exact unchanged original IGCSE Booklet 21 – Solving Quadratic Equations | Original 22-page PDF.

Keep the original page, question and subpart numbers when following the matching lesson recordings. Each recording may cover selected examples; the complete PDF includes additional practice. This is the original teaching booklet, with its original historical labels and layout.

Spiral learning connection: connect these skills to earlier number, algebra and modelling ideas, then return to them in later problems.

Original-edition clarifications (the PDF itself is unchanged):

• Page 8, the printed Q17(k) answer has a sign typo. For 3x² − 2x − 7 = 0, the correct roots are (1 − √22)/3 and (1 + √22)/3.

• Page 11, Q19(c)(ii): the quadratic f(x) = x² − x − 2 is not one-to-one on all real numbers. The two preimages of 0 are −1 and 2; a single-valued inverse function requires a stated domain restriction.

• The recording of Q29(b)(iii) rounds x too early and shows 26.44 cm. Retain x = 1 + √13: the perimeter is 12 + 4√13 ≈ 26.42 cm to two decimal places.