2 Mathematical Formulae 1. ALGEBRA Quadratic Equation For the equation ax2 + bx + c = 0, x= - b ! b 2 - 4ac . 2a Binomial Theorem () () () () n n n (a + b)n = an + 1 an–1 b + 2 an–2 b2 + … + r an–r br + … + bn, n n! . where n is a positive integer and r = (n – r)!r! 2. TRIGONOMETRY Identities sin2 A + cos2 A = 1 sec2 A = 1 + tan2 A cosec2 A = 1 + cot2 A Formulae for ∆ABC a b c = = sin A sin B sin C a2 = b2 + c2 – 2bc cos A ∆= © UCLES 2018 1 bc sin A 2 0606/12/O/N/18 6 1.4 You must not use a calculator in Question 4. For Examiner’s Use In the triangle ABC, angle B = 90°, AB = 4 + 2 2 and BC = 1 + 2 . (i) Find tan C, giving your answer in the form k 2 . [2] (ii) Find the area of the triangle ABC, giving your answer in the form p + q 2, where p and q are integers. [2] (iii) Find the area of the square whose side is of length AC, giving your answer in the form s + t 2, where s and t are integers. [2] © UCLES 2011 0606/12/M/J/11 11 2.9 The figure shows a circle, centre O, radius r cm. The length of the arc AB of the circle is 9π cm. Angle AOB is θ radians and is 3 times angle OBA. O r cm For Examiner’s Use A θ rad 9π cm B 3π (i) Show that θ = 5 . [2] (ii) Find the value of r. [2] (iii) Find the area of the shaded region. [3] © UCLES 2011 0606/12/M/J/11 [Turn over www.theallpapers.com 7 3.5 A r cm O θ rad B The diagram shows a circle with centre O and radius r cm. The minor arc AB is such that angle AOB is i radians. The area of the minor sector AOB is 48 cm2. 96 . r2 [2] (i) Show that i = (ii) Given that the minor arc AB has length 12 cm, find the value of r and of i. [3] (iii) Using your values of r and i, find the area of the shaded region. [2] © UCLES 2018 0606/11/O/N/18 [Turn over 14 11 4. P Q r cm i rad O The diagram shows the sector OPQ of a circle, centre O, radius r cm, where angle POQ = i radians. The perimeter of the sector is 10 cm. (i) Show that area, A cm2, of the sector is given by © UCLES 2018 A= 0606/12/O/N/18 50i . (2 + i) 2 [5] 15 It is given that i can vary and A has a maximum value. (ii) Find the maximum value of A. [5] Question 12 is printed on the next page. © UCLES 2018 0606/12/O/N/18 [Turn over