PORT SHEPSTONE ISLAMIC SCHOOL MATHEMATICS INVESTIGATION GRADE 8 TERM 2 2022 EXAMINER: B GUNDANI MODERATOR: I ATCHA TIME: 1 Hour TOTAL: 50 NAME :…………………………………………………….. CLASS:……………… NSTRUCTIONS AND INFORMATION 1. This investigation consists of 7 questions. 2. Answer ALL the questions. 3. Number the answers correctly according to the numbering system used in this question paper. 4. Write neatly and legibly. Question Mark 1 2 3 4 5 6 7 TOTAL This investigation consists of 6 pages. Investigation: Exponents, Numeric and Geometric Patterns [Turn over 2 QUESTION 1 1.1 Write the following in exponential form, state your answer as a single exponent.( e.g 2a or 5b) 1.1.1 2 × 2 × 2 (1) 1.1.2 2 × 2 × 2 × 2 × 2 (1) 1.1.3 (2 × 2 × 2) × (2 × 2 × 2 × 2 × 2) (1) 1.1.4 5 × 5 × 5 × 5 (1) 1.1.5 5 × 5 × 5 × 5× 5 × 5 (1) 1.1.6 (5 × 5 × 5 × 5) × (5 × 5 × 5 × 5× 5 × 5) (1) 1.2 Use your answer to 1.1.3 to write down the answer in exponential form of : 23 × 25 (1) 1.3 Use your answer to 1.1.6 to write down the answer in exponential form of : 54 × 56 (1) 1.4 From your observation in 1.1.3 and your answer to 1.2, complete the box below with the correct operation ( + , × , –, ÷ ) 23 × 25 = 23 5 _ 1.5 (1) From your observation in 1.1.6 and your answer to 1.3, complete the box below with the correct operation ( + , × , –, ÷ ) 54 × 56 = 54 6 (1) 1.6 In terms of m and n : am × an = (1) [11] 3 QUESTION 2 2.1 Write the expression 2 2 2 2 2 2a in exponential form b 2 2 2 (1) 2.2 Simplify, write your answer in exponential form : 2 2 2 2 2 2 2 (1) 2.3 Write the expression 5 5 5 5 5 5 5 5 5 5 5a in exponential form 5b (1) 2.4 Simplify, write your answer in exponential form 5 5 5 5 5 5 5 5 5 5 (1) 2.5 From your observation in 2.1 and your answer to 2.2, complete the box below with the correct operation ( + , × , –, ÷ ) 25 ÷ 22 = 25 2 (1) 2.6 From your observation in 2.3 and your answer to 2.4, complete the box below with the correct operation ( + , × , –, ÷ ) 57 ÷ 53 = 57 3 (1) 2.7 In terms of m and n : am ÷ an = (1) [7] QUESTION 3 Study the following two examples: Example 1 : a 2 a2 a2 a 2 3 = (a × a) × (a × a) × (a × a) = a6 Example 2 : 54 = 5 4 5 4 2 = ( 5 × 5 × 5 × 5 ) × ( 5 × 5 × 5 × 5) = 58 4 3.1 Use the same method in Examples 1 and 2 above to simplify : 3 3 4 × = × )×( =( (1) × )×( )×( ) = 3.2 (1) (1) From your observation in Example 1, 2 and 3.1 above, complete the box below with the correct operation ( + , × , –, ÷ ) a = a2 3 2 3 (1) 3.3 In terms of m and n : a m = n (1) [5] QUESTION 4 2 2 2 2 2 4.1 Write the expression 2 2 2 2 2 in exponential form 2a 2b (1) 4.2 Simplify the expression : 2 2 2 2 2 2 2 2 2 2 (1) 4.3 Using the law you discovered in 2.7, simplify the expression in the form 2a (1) 4.4 From your observation : x0 = (1) [4] QUESTION 5 APPLICATION OF EXPONENTIAL LAWS Using the exponential laws you discovered above, simplify the following, state the answer in exponential form: 5.1 34 × 39 (1) 5.2 5x2 × 4x5 (1) 5 5.3 912 ÷ 95 (1) 5.4 64x7 ÷ 8x4 (1) 5.5 a 5 4 (1) 5.6 3a 2 2 (1) 5.7 110 (1) [7] QUESTION 6 Given the sequence: 6.1 7 ; 11 ; 15 ; 19 ; . . . Write down the next two terms in the sequence. (2) 6.2 Describe the relationship between the terms. (2) 6.3 Write a formula in terms of n to describe the relationship between the position of a term in the sequence and term itself. (2) 6.4 Use your formula in 6.3 to find the 20th term. (2) [8] 6 QUESTION 7 A factory makes window frames. Type 1 has one window pane, type 2 has four window panes, type 3 has nine window panes, and so on Type 5 7.1 In the space above draw type 5 window frame. 7.2 How many window panes will there be in type: (2) 7.2.1 5? (1) 7.2.2 6? (1) 7.3 Copy and complete the table below: Frame type 1 2 3 4 Number of window panes 1 4 9 16 5 6 15 20 (2) 7.4 How many window panes will be in type n? (2) [8] GRAND TOTAL : 50