Why ##a^0=1##?

  • Context: Undergrad 
  • Thread starter Thread starter Mike_bb
  • Start date Start date
  • #31
Equation 1 has no solution: ##2^x > 0## for all ##x \in \mathbb{R}##. The only "value" satisfying ##2^x = 0## is ##x = -\infty##, which is not a real number, and certainly cannot equal ##0##.
 
  • Like
  • Love
Likes   Reactions: sophiecentaur, bhobba and Mike_bb
Physics news on Phys.org
  • #32
Mike_bb said:
I decided to solve following equations:

Where in the world did you even get this from?
 
  • Like
Likes   Reactions: sophiecentaur, bhobba and Roberto Pavani
  • #33
Mike_bb said:
I decided to solve following equations:

1) Let 2x =0
Your reality check should kick in here, at this stage. Your equation 1) has to be dodgy. We've all agreed that 20 = 1 and all the various 'justifications / proofs are up there.
Any magnitude less than 1 has to be 2 raised to the power of a number less than zero (a negative number). Smaller would be more negative. Think of a log scale graph (just to get pictorial); smaller numbers need more and more negative powers of 2, which means further and further left along the X axis. Your piece of paper would need to be infinitely wide, to the left.
If the idea came from someone else than check before you believe anything else they say. If it came from you then just give your head a wobble. and 'Look before you leap.'.etc. :wink:
 
  • Like
Likes   Reactions: bhobba
  • #34
Ibix said:
If you have a number and you choose not to multiply it by anything, should it turn into a zero? Or should it stay the same?
This seems logical to me.

But after rereading, your second post confused me:

Ibix said:
Exactly. So you want "multiply by no a's" to be "multiply by 1".

How is it possible "to multiply number by no a's"? I understand when ##1## is at the beginning (##1*a*a..a##). But as I understood you meant ##a*a*a*a*...*1##. Give me more details please. Thanks.
 
  • #35
Mike_bb said:
I understand when 1 is at the beginning (1∗a∗a..a). But as I understood you meant a∗a∗a∗a∗...∗1.

What's the difference? Multiplication is commutative, you can write 1 wherever you want.

My thought: you are overcomplicating things.
 
  • Agree
Likes   Reactions: Mike_bb
  • #36
Mike_bb said:
How is it possible "to multiply number by no a's"?
You just don't do anything. Which you want to be the same as multiplying by 1.
 
  • #37
I can't understand how does it work if ##x*x*x*x^0##?

Ibix said:
You just don't do anything. Which you want to be the same as multiplying by 1.
  • x³ = 1 × x × x × x
  • x² = 1 × x × x
  • x¹ = 1 × x
  • x⁰ = 1 (we multiply by x zero times, leaving just the starting 1)
 
  • #38
I don't understand your problem. You've stated correctly in your bullets that ##x^0=1##, so you know that ##x\cdot x \cdot x\cdot x^0=x^3##. What's the problem?
 
  • #39
Ibix said:
I don't understand your problem. You've stated correctly in your bullets that ##x^0=1##, so you know that ##x\cdot x \cdot x\cdot x^0=x^3##. What's the problem?
When you wrote post#2 you probably meant that "to multiply number by no a's" = ##a*a*a*a^0##. I can't understand how did you infer that ##a^0=1## from this expression?
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 25 ·
Replies
25
Views
5K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 29 ·
Replies
29
Views
6K