## anonymous 3 years ago √(2x-1)=-3 Help?

1. jiteshmeghwal9

by squaring both sides$2x-1=9$

2. anonymous

$\sqrt{2x - 1} = -3$ Square on both sides. $2x - 1 = 9$ Quite simple now, can you do it?

3. jiteshmeghwal9

solve for 'x' from here

4. anonymous

don't even start this problem $$\sqrt{2x-1}$$ is positive, whereas $$-3$$ is negative, so there is no solution

5. anonymous

don't square both sides, don't do anything at all a positive number cannot equal a negative one say "no solution" and be done

6. anonymous

which is good example of making sure you think before you apply some method to a problem

7. anonymous

Hmm... the sqrt(9) isn't -3, but I don't see how that disallows -3^2

8. anonymous

i am assuming you are looking for a real value for $$x$$ and not two complex numbers whose square is $$-3$$

9. jiteshmeghwal9

but @satellite73 sir this gives the condition of the question but he needs to solve for 'x'

10. anonymous

I didn't think from that point of view.

11. anonymous

That was a good point.

12. anonymous

Allright, I think I'm getting it. Thanks for all the help. :)

13. anonymous

if so (and i really really doubt it) then this method $2x-1=9$ $2x=10$ $x=5$ will certainly not work, and the check is easy $\sqrt{2\times 5-1}=\sqrt{9}=3\neq -3$

14. jiteshmeghwal9

hmmmm......

15. jiteshmeghwal9

u r right sir :) sorry!

16. anonymous