Letters in expressions and formulas


by Grog85
Tags: expressions, formulas, letters
Grog85
Grog85 is offline
#1
Feb5-14, 08:21 AM
P: 2
Hello, first post for me so I am sorry if this is in the wrong topic.

I'm am from the UK studying A-Level Physics.

I understand some formulas but this is testing me. Before I message my tutor I thought I would try here. Looks like a very useful website.

Letters in expressions and formulas.

v2 = u2 + 2as

I normally understand maths when I know the rules.

2 5 is written as 2 5 or 10
2 a is written as 2a
a b is written as ab

I don't seem to understand this and I can't seem to find helpful information and I will not skip the page.

Sorry if this is in the wrong topic and thank you for your help.
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DrClaude
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#2
Feb5-14, 08:30 AM
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Quote Quote by Grog85 View Post
v2 = u2 + 2as
Do you mean ##u^2## and ##v^2##, with the 2 small and high? In that case, it is called an exponent and, in the present case, means "squared":
$$
u^2 = u \times u
$$
and
$$
v^5 = v \times v \times v \times v \times v
$$
You can have a look at Wikipedia for what it means when the exponent is not a positive integer.
Mentallic
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#3
Feb5-14, 08:32 AM
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Multiplication is used so much in maths that it's simply much easier to get rid of the [itex]\times[/itex] symbol. This also meant that the letter [itex]x[/itex] could be used as a variable (and it's used a lot) without running into problems of ambiguity between it being a variable or a multiplication symbol.

Whenever you have a situation like [itex]2\times 5[/itex] then you're expected to evaluate that to 10, while [itex]2\times a=2a[/itex] cannot be simplified further so it's ok to leave as it is.

Other than that, I don't see what's so confusing about the notation.

Grog85
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#4
Feb5-14, 08:41 AM
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Letters in expressions and formulas


Quote Quote by DrClaude View Post
Do you mean ##u^2## and ##v^2##, with the 2 small and high? In that case, it is called an exponent and, in the present case, means "squared":
Yes, small 2 above the u.

Thank you for your help. I'll see how I get on.
SteamKing
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#5
Feb5-14, 09:22 AM
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You must have missed a couple of days in algebra class.
Mark44
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#6
Feb5-14, 12:07 PM
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Grog85, if you're going to be studying physics, you'll need to get the algebra difficulties squared away first.
PeroK
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#7
Feb5-14, 12:15 PM
P: 334
Grog85, there a site here that covers all the A-level maths topics:

http://www.examsolutions.net/


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