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## hogie 2 years ago Simplifying radical expressions.

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1. hogie

$\sqrt{4a^2}$

2. hogie

|dw:1366344988992:dw|

3. hogie

What do i do with the a^2

4. hogie

?

5. hogie

|dw:1366345074437:dw|

6. dave0616

a is squared, and the opposite of a square root is to the second power. because this expression can also be written as (4a^2)^1/2. so if you take 2 and multiply it by a half, you get 1. so the answer is 2a

7. hogie

|dw:1366345329452:dw|

8. dave0616

same principle is used. (4x^4)^1/2, 4*(1/2)=2= 2x^2

9. hogie

|dw:1366345558930:dw|

10. dave0616

correct

11. hogie

|dw:1366345964027:dw|

12. dave0616

i wanna help you through this one. what is x*x*x*x?

13. hogie

|dw:1366346145214:dw|

14. hogie

you can only pull two x's out right?

15. dave0616

that is correct. so now you have sqrt(x^4). well in a way yes, but lets go ahead and use the formula we had.: (x^4)^1/2 4*(1/2)=2

16. dave0616

so you have x^2

17. hogie

|dw:1366346262015:dw|

18. hogie

That would be the answer? ^^^

19. dave0616

nope, because you origonally had :$\sqrt{x^{4}}$ and you took the square root of that to get x^2

20. hogie

So what would it be? Just x^2

21. hartnn

$$\large \sqrt{9x^4}= 3x^2$$ is correct.

22. dave0616

@hartnn and @hogie i guess i am confused as to where the sqrt(9x^4) came from, because i dont see that any where, thought 3x^2 would be correct for that

23. hartnn

|dw:1366347228041:dw|

24. dave0616

ohhhh i mistook that as a four, im sorry, then yes 3x^2 would be correct

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