2.3.1 Try some yourself
Activity 22
Write the following as one number to a single power:
(a) 23 × 24
(b) 32 × 34
(c) 42 × 43 × 44
Answer
(a) 23 × 24 = 2(3 + 4) = 27
(b) 32 × 34 = 3(2 + 4) = 36
(c) 42 × 43 × 44 = 4(2 + 3 + 4) = 49
Activity 23
Without using your calculator, find the following, as estimates for calculation work in the next question.
(a) (−1)5
(b) 34
Answer
(a) (−1)5 = −1 (any odd power of −1 is −1)
(b) 34 = 3 × 3 × 3 × 3 = 81
Activity 24
Use your calculator to find the following.
(a) (−1.3)5
(b) 3.24
(Use your answers to the previous question as rough checks.) Round your answers to four decimal places.
Answer
(a) (−1.3)5
−3.7129(b) 3.24 = 104.8576