Help a newbie with a calculation result
09-14-2017, 05:24 PM
Post: #1
 Skfir Junior Member Posts: 5 Joined: Sep 2017
Help a newbie with a calculation result
Hi guys. Sorry, I am a pianist, doing math for the sake of self-education. SO I am quite stupid in it. I enter the following in my HP Prime: -2^4 and it gives me the result -16, but shouldn't it be positive 16? because -2*-2*-2*-2=16?
Sorry apparently I am just dumb, but please explain.
09-14-2017, 05:49 PM (This post was last modified: 09-14-2017 05:51 PM by salvomic.)
Post: #2
 salvomic Senior Member Posts: 1,364 Joined: Jan 2015
RE: Help a newbie with a calculation result
(09-14-2017 05:24 PM)Skfir Wrote:  Hi guys. Sorry, I am a pianist, doing math for the sake of self-education. SO I am quite stupid in it. I enter the following in my HP Prime: -2^4 and it gives me the result -16, but shouldn't it be positive 16? because -2*-2*-2*-2=16?
Sorry apparently I am just dumb, but please explain.

hi,
is a problem of "order of operations" (see here).
(-2)^4 is 16, instead -2^4 is the same as (-2)^4 that's simply -16.
-2*-2*-2*-2 is seen with *implicit (), but not the power (-2^4)...

Salvo

∫aL√0mic (IT9CLU), HP Prime 50g 41CX 71b 42s 12C 15C - DM42 WP34s :: Prime Soft. Lib
09-14-2017, 05:50 PM
Post: #3
 John Colvin Member Posts: 166 Joined: Dec 2013
RE: Help a newbie with a calculation result
The result is correct because of the order of operations. Powers and roots are evaluated
before addition/subtraction and signs, You get the result +16 by entering
(-2)^4 where parentheses take precedence over the other operations.
09-14-2017, 05:52 PM (This post was last modified: 09-14-2017 05:55 PM by DrD.)
Post: #4
 DrD Senior Member Posts: 1,032 Joined: Feb 2014
RE: Help a newbie with a calculation result
No, you are not dumb. (-2)^4 is 16. However you have entered -2^4, which is -1*(2^4), which is -16.

-Dale-
09-14-2017, 06:13 PM
Post: #5
 Aries Member Posts: 89 Joined: Oct 2014
RE: Help a newbie with a calculation result
(09-14-2017 05:24 PM)Skfir Wrote:  Hi guys. Sorry, I am a pianist, doing math for the sake of self-education. SO I am quite stupid in it. I enter the following in my HP Prime: -2^4 and it gives me the result -16, but shouldn't it be positive 16? because -2*-2*-2*-2=16?
Sorry apparently I am just dumb, but please explain.

That result is correct, you have to take note of the parenthesis:
-2^4=-16, (-2)^4=+16.
Best,

Aries ;-)
09-14-2017, 09:06 PM
Post: #6
 Skfir Junior Member Posts: 5 Joined: Sep 2017
RE: Help a newbie with a calculation result
Oh!! Got it!! Thank you guys!!
09-15-2017, 06:08 PM
Post: #7
 Aries Member Posts: 89 Joined: Oct 2014
RE: Help a newbie with a calculation result
You are welcome, Skfir ;-)
Best,

Aries :-)
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