(a) If (3 - x), 6, (7 - 5x) are consecutive terms of a geometric progression (GP) with constant ratio r > 0, find the : (i) values of x ; (ii) constant ratio. (b) In the diagram, |AB| = 3 cm, |BC| = 4 cm, |CD| = 6 cm and |DA| = 7 cm. Calculate <ADC, correct to the nearest degree.
Explanation
(a) (i) (3 - x), 6, (7 - 5x). First term = a = (3 - x) common ratio = (ii) Constant ratio = Using x = 5, = (b) Considering AOC Considering ACD, Using cosine rule, = = (to the nearest degree)