Question

The equation x^3-6x=72 has a solution between 4 and 5. Use a trial and improvement method to find this solution. Give your answer correct to 1 decimal place. You must show all your working. On the same line as your final answer you must write ‘to 1 decimal place’

Answer 1

Answer:

4.6

Step-by-step explanation:

x³-6x=72

x³-6x-72=0   .... a solution between 4 and 5

x=4             x³-6x-72= 64-24-72 = -32

x=5             x³-6x-72= 125-30-72 = 23

we have to find an x value that makes x³-6x-72 --> 0

see the attachment, we can find the 0 value of x is between 4.63 and 4.64

‘to 1 decimal place’ of the solution is: 4.6 (4.63 is too small and 4.64 is too big)