Should -3^2 be (-3)^2 or -(3^2)?  TOPIC_SOLVED

Simplificatation, evaluation, linear equations, linear graphs, linear inequalities, basic word problems, etc.

Should -3^2 be (-3)^2 or -(3^2)?

Postby Hyacinth on Tue Nov 23, 2010 2:30 am

If I see -3^2 on a math placement test, should it be (-3)^2 (which equals 9) or -(3^2) (which equals -9). I read on a math web site that it should be the latter -- that the exponent makes the parentheses around 3^2 implicit. But a an instructional algebra book I have supplies answers to problems that make it apparent that the book is going with the former situation.

Thank you!
Hyacinth
 
Posts: 1
Joined: Tue Nov 23, 2010 2:25 am

Sponsor

Sponsor
 

  TOPIC_SOLVED

Postby stapel_eliz on Tue Nov 23, 2010 11:22 am

It should definitely be the latter! The negative of a square is a negative value! :shock:
User avatar
stapel_eliz
 
Posts: 1720
Joined: Mon Dec 08, 2008 4:22 pm

Re: Should -3^2 be (-3)^2 or -(3^2)?

Postby sio6627 on Fri Dec 10, 2010 3:45 pm

(-3)^2 however is a positive value because a negative times a negative is a positive?
(-3) * (-3) = 9

right? -- rather than - (3^2) which is - (9) = -9

-sio.
sio6627
 
Posts: 1
Joined: Fri Dec 10, 2010 3:40 pm

Postby stapel_eliz on Fri Dec 10, 2010 7:37 pm

sio6627 wrote:(-3)^2 however is a positive value because a negative times a negative is a positive?

Yes; (-3)2 = (-3)(-3) = +9. But the poster was asking about -32, which is -(32) = -(3)(3) = -9. :wink:
User avatar
stapel_eliz
 
Posts: 1720
Joined: Mon Dec 08, 2008 4:22 pm


Return to Beginning Algebra