Projectively extended real line
In real analysis, the projectively extended real line (also called the one-point compactification of the real line, or simply real projective line), is the extension of the number line by a point denoted ∞. It is thus the set 
(where 
is the set of the real numbers), sometimes denoted by 
The added point is called the point at infinity, because it is considered as a neighbour of both ends of the real line. More precisely, the point at infinity is the limit of every sequence of real numbers whose absolute values are increasing and unbounded.
The projectively extended real line may be identified with the projective line over the reals in which three specific points (e.g. 0, 1 and ∞) have been chosen. The projectively extended real line must not be confused with the extended real number line, in which +∞ and −∞ are distinct.
Dividing by zero
Unlike most mathematical models of the intuitive concept of 'number', this structure allows division by zero:
for nonzero a. In particular 1/0 = ∞, and moreover 1/∞ = 0, making reciprocal, 1/x, a total function in this structure. The structure, however, is not a field, and division does not retain its original algebraic meaning in it, as witnessed for example by 0⋅∞ being undefined despite reciprocation being total. The geometric interpretation is this: a vertical line has infinite slope.
RP-1
RP-1 (alternately, Rocket Propellant-1 or Refined Petroleum-1) is a highly refined form of kerosene outwardly similar to jet fuel, used as rocket fuel. Although having a lower specific impulse than liquid hydrogen (LH2), RP-1 is cheaper, stable at room temperature, far less of an explosion hazard and far denser. RP-1 is significantly more powerful than LH2 by volume. RP-1 also has a fraction of the toxicity and carcinogenic hazards of hydrazine, another room-temperature liquid fuel. Thus, kerosene fuels are more practical for many uses.
Usage and history
RP-1 is most commonly burned with LOX (liquid oxygen) as the oxidizer, though other oxidizers have also been used. RP-1 is a fuel in the first-stage boosters of the Soyuz-FG, Zenit, Delta I-III, Atlas, Falcon 9, Antares and Tronador II rockets. It also powered the first stages of the Energia, Titan I, Saturn I and IB, and Saturn V. ISRO is also developing a RP-1 fueled engine for its future rockets.
During and immediately after World War II, alcohols (primarily ethanol, occasionally methanol) were the single most common fuel for large liquid-fueled rockets. Its high heat of vaporization kept regeneratively cooled engines from melting, especially considering that alcohols would typically contain several percent water. However, it was recognized that hydrocarbon fuels would increase engine efficiency, due to a slightly higher density, the lack of an oxygen atom in the fuel molecule, and negligible water content. Whatever hydrocarbon was chosen, though, would have to replicate alcohol's coolant ability.
RP 1
RP 1, RP-1, RP.1, RP1, or variant may refer to:
- 5580 Sharidake or 1988 RP1, asteroid Sharidake, RP1 from 1998, the 5580th asteroid catalogued
- (12728) 1991 RP1, RP1 from 1991, the 12728th asteroid catalogued
- 12576 Oresme or 1999 RP1, asteroid Oresme, RP1 from 1999, the 12576th asteroid catalogued
See also
Podcasts:
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by Dave East
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by A-1
A-1
by: Dave EastA 1 nigga and it go
Life is a bitch and then you gotta die
Killing these niggas ...ain't gotta try
The truth is set you free so I ain't gotta lie
We from the bottom, kick the bottom, that's the bottom line
I wasn't the kid that teachers like
Holly with the church ain't live the preachers life
I have my eyes on the preacher wife
Devil got my conscience how the fuck I'm 'pose to sleep at night?
I remember nights I wan't eating right
Smoking so much 'I wasn't breathing right
These was just bookers never will read as right
Late night we're hookers bunching my hit in time
Spending riffs in the trap thinking I need a life
You wanna ride pick a side but on this side this shit is life
Talking and still just pop me a half of a pill
My nigga I'm own it on the dark
Forgive me for all the sins hope that I wake up in the morning
I'mma hustle 'til my day come
Hustle in quite try to my case come
Standing on the couch and popping bottles 'til the case drop
Tell me what you need I got that work and bitch is A1
Put that on A1, codeine A1
Cush smoke A1, wiping code A1
Stressing out A1, back it up A1
Bringing back A1, my hood's working got good work
My life falling you time line they jamming on your playlist
My bicthes soke at they own money
All your bitches it's basic
Nineteen I have to pay rent I was outside you stayed in
Half on my niggas it's catch in and the other half will stay friends
With this new work named A1 drop that when they taste this
One fine but we ain't kicks, let me hold this out of great eight six
Smoking out all this bank account
That A1 make 'em take it out
Fucked up you eat it out I got hit, you was make it up disgusting
You want a verse with your budget
I cover first with a busting
I ain't hard to find I'm in public
Had all the diamonds and I'm clicking
Up in the studio dogging, I was dog double of my mission
No growd it I smoke nuggets
No pirax in that kitchen, she's back, Jesus and I digging scales
Apologize to my mama, both of her sons been in jail
We couldn't avoid that bullshit
On that chain we took that right back on these cold streets
Walk in if I won't push back, still high and piegual, we book that
I'mma hustle 'til my day come
Hustle in quite try to my case come
Standing on the couch and popping bottles 'til the case drop
Tell me what you need I got that work and bitch is A1
Put that on A1, codeine A1
Cush smoke A1, wiping code A1
Stressing out A1, back it up A1
Bringing back A1, my hood's working got good work
We're all mad, we're all hear
This ain't chance to blow,
What you'll call at they call back but my phone it's broke
Change my number, got gunners, don't run after smoke
When that keep come, my day one got A1 for sure
Say they all mad, they all heart this ain't chance to blow
This ain't chance to blow,
What you'll call at they call back but my phone it's broke
Change my number, got gunners, don't run after smoke
When that keep come, my day one got A1 for sure
I'mma hustle 'til my day come
Hustle in quite try to my case come
Standing on the couch and popping bottles 'til the case drop
Tell me what you need I got that work and bitch is A1
Put that on A1, codeine A1
Cush smoke A1, wiping code A1
Stressing out A1, back it up A1
Bringing back A1, my hood's working got good working
My hood's working got good working
My hood's working got good working
My hood's working got good working
A1 nigga, A1 nigga, peace