+0  
 
0
44
1
avatar

https://vle.mathswatch.co.uk/images/questions/question1296.png

 Nov 23, 2020
 #1
avatar
0

x^3 - 10x =100

 

The question is asking you to use trial and error method to find x.

So, start with x = 5. Sub 5 for x in the above equation.

 

5^3 - 10*5 =100

125 - 50 =75 . So, 5 is too small. Try 5.5

5.5^3 - 5.5*10 =

166.375 - 55 =111.375 now, that is a bit better than 5 but is little too big. So, try 5.3

5.3^3 - 5.3*10 =

148.877 - 53 =95.877 now, that is much closer to 100 but is still a bit too small. So, try 5.4

5.4^3 - 5.4*10 =

157.464 - 54 =103.464 now, that is the closest to 100 so far. Since, they want you to try and get the value of x accurate to "1 decimal place", then:

x = 5.4 accurate to 1 decimal place. And that is it!.

 Nov 23, 2020

22 Online Users

avatar
avatar
avatar