Solving the Inequality: How to Find the Solution for (a-x+1)(a-x+2) ≤ a?

  • Level: High School 
  • Thread starter Thread starter nightking
  • Start date Start date
  • Tags Tags
    Inequality
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
3 replies · 2K views
nightking
Messages
2
Reaction score
0
How can I solve this inequality?

(a-x+1)(a-x+2) ≤ a

where a is a constant with unknown value.

Thanks in advance.
 
Mathematics news on Phys.org
Hey nightking and welcome to the forums.

You need to expand out the left hand side and then put on side completely in terms of x.

The rules for inequalities are that you can't divide any side by zero (you also have to make sure any variables you have are not zero either if you want to divide), if you divide by a negative number you flip the inequality sign, if you subtract or add a term the sign doesn't change.
 
If you want to find x in terms of a, I would start with
((a - x + 3/2) - 1/2)((a - x + 3/2) + 1/2) ≤ a

The left hand side is then the difference of two squares...
 
AlephZero said:
If you want to find x in terms of a, I would start with
((a - x + 3/2) - 1/2)((a - x + 3/2) + 1/2) ≤ a

The left hand side is then the difference of two squares...

Brilliant. Thanks!