Trial & improvement x2 -4x = 10 x2 on calculator squared button
x x2 -4x comment
5 52 -4 x5 =5 too small
6 62 -4 x6 =12 too large
5.5 5.5.2 -4 x5.5 =8.25 too small
5.7 5.7.2 -4 x5.7 =9.69 too small
5.8 5.8.2 -4 x5.8 =10.44 too large
5.75 5.75.2 -4 x5.75 =10.0625 too large
answer = 5.7
mode set up button select 3 = table
f(x)= appears
press alpha button  
press ) button  
f(x)=x appears
pressx3 button  
f(x)=x3 appears
press alpha button  
press ) button  
f(x)=x3 -x appears
press = button  
start appears
insert 4  
press = button  
start ends appears
start  
insert 0.1  
press = button  
table appears on calculator
to re enter and edit table integers input
press ac button once only
or it will revert to start of whole process
re enter start say at 5.7
re enter say end at 5.8
then 0.01 = table opens again