Analysis and Approaches for IBDP Maths Ebook 1 | Page 148

Your Practice Set – Analysis and Approaches for IBDP Mathematics (b) (c) (d) (e) The total surface area 2 �2�r � 2�rh (M1) for valid approach 2 �2 �(30) � 2 �(30)(45) (A1) for substitution � 14137.16694 2 � 14100 cm A1 N3 1 V 3 1 � 3 � (A1) for substitution OV � 75.9375 cm A1 N3 2 � � r h (M1) for valid approach 2 127234.5025 (40) (OV) ˆ OV tan VAO � OA (M1) for tangent ratio ˆ 75.9375 tan VAO � 40 VAO ˆ � 62.22202722 VAO ˆ � 62.2 A1 N2 The slant height l 2 2 � � (M1) for finding slant height 75.9375 40 � 85.82833976 The total surface area 2 ��r � �rl (M1) for valid approach 2 ��(40) � �(40)(85.82833976) (A1) for substitution � 15812.05551 2 � 15800 cm A1 N2 [3] [3] [2] [4] Exercise 49 1. A solid metal hemisphere has a base radius of 10 cm. (a) Find the volume of the hemisphere. [3] (b) Find the total surface area of the hemisphere. [3] Four identical hemispheres were melted and recast into a solid circular cone, shown in the following diagram. The base diameter AB is 38 cm. 140 SE Production Limited