Pearson Edexcel International GCSE   P69196A ©2022 Pearson Education Ltd. L:1/1/1/1/ *P69196A0228* 2  International GCSE Mathematics Formulae sheet – Higher Tier Arithmetic series Sum to n terms, Sn = n 2 [2a + (n – 1)d] Area of trapezium = 1 2 (a + b)h b a h The quadratic equation The solutions of ax2 + bx + c = 0 where a ¹ 0 are given by: x b b ac a = − ± − 2 4 2 Trigonometry A B C b a c In any triangle ABC Sine Rule a A b B ...