géométrie sphérique

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Enregistré le : 19 oct. 2020 14:58

géométrie sphérique

Message par MosleyCale » 19 oct. 2020 15:04

Best Pressure Washer Reviews

A pressure washer can shoot dust, mud, and dirt from surfaces through a nozzle. However, It’s challenging to find the right one among so many brands of choices.

Our pressure washer reviews today will help you choose the top performers that can blast things clean in a minute. With this powerful machine, you do not just clean stubborn stains, but also bring the beauty back to your property in no time.

Picked For You: Best pressure washers reviews - The top rated pressure washer

Top 3 pressure washer reviews of 2020

We’ve tested and reviewed these 3 best pressure washers to help you get the most suitable one for your cleaning tasks. Keep scrolling to know how to finish the job effortlessly.

1. Simpson MSH3125-S Pressure Washer

After browsing through different power washers, we’ve finally stopped at the Simpson MSH3125-S model. It’s a gas-powered pressure washer and equipped with a GCV190 engine of Honda.

The engine is often reliable as they used to be from the start. It offers the full 3100 psi and amazing performance.

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With such a decent engine, you can trust the cleaning power and its durability of Simpson pressure washer after long use. Whether it’s a driveway, car, or concrete surface, the machine still offers fantastic performance for your minimal effort.

Better than that, it’s portable and lightweight so that any homeowner can carry it along everywhere else. Another part of MSH3125 you’ll also love would be its premium pneumatic tires. By having them, feel free to move the machine up and down on any uneven surface.

2. Nilfisk E 145 Bar Power Washer

If you wonder which one is the most powerful pressure washers in the lineup of Nifisk, then this E 145 model can score high in all of the performance tests and it is one of Good pressure washer brands.

With a tough turbo nozzle, the cleaner seems to excel at removing dirt on larger surfaces. The nozzle pattern also makes it easier for you to change between attachable accessories.

No doubt, the Nilfisk E 145 is a domestic pressure washer that offers a high level of durability, flexibility, and comfort. But what we love most about it is its telescopic handle. This enables adjustment based on who uses it, making your work comfortable for everyone.

It just does all heavy work for you, making your cleaning projects faster and easier.

Let’s move it around the yard, which is all thanks to the cleaner’s trolley design.

and start giving your place a makeover.

3. Generac 6565

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The Generac 6565 is an expert grade power washer for home use that is worth your attention this time. Generac is one of the top-rated brands manufacturing the pressure washers in the market. It has existed since 1959 and has built a trusted name in this industry.

Its engine offers the highest performance at the most rugged terrains. With 4,200 PSI, the Generac 6565 is one of the most powerful cleaners out there, so it’s best for the toughest cleaning tasks.

Since the model is bigger than a few other pressure washers, so it has high wheel support. There are big and pneumatic tires on this machine. They help offer ease of use and shock absorption, which let them be stable on rugged surfaces.

Final words

Through these Best pressure washers reviews, we hope that you can find a suitable one fitting your needs. No matter if the property is big or not, the washer can help remove the dirt in no time. As long as you’ve got a good-quality machine, you can do it in less time and also save a lot of bucks.
Modifié en dernier par MosleyCale le 25 avr. 2021 16:13, modifié 2 fois.

Messages : 2206

Enregistré le : 27 oct. 2017 10:55

Classe : Bac a fleurs

Re: géométrie sphérique

Message par Hibiscus » 19 oct. 2020 15:59

S'agit-il de la loi $ \cos c = \cos a \, \cos b + \sin a \, \sin b \, \cos\gamma, $ dans un "triangle" comme celui-ci ? https://upload.wikimedia.org/wikipedia/ ... ations.png

Auquel cas, ca peut se demontrer comme suit :

On prend un "triangle spherique" (je sais pas trop comment ca s'appelle) ABC, dans une sphere (O,1). Un bon vecteur a regarder est $ \vec{OA}-\cos b~\vec{OC} $.
SPOILER:
Alors $ \vec{OA}-\cos b~\vec{OC} $ est tangent en C au cercle passant par A et C.
(parce que dans le plan OAC, et orthogonal a $ \vec{OC} $ par definition.
et $ || \vec{OA}-\cos b~\vec{OC}||=\sin b $
On fait la meme chose avec $ \vec{OB}-\cos a~\vec{OC} $, de norme $ \sin a $

Le produit scalaire des deux vecteurs donne alors $ \sin a \sin b \cos \gamma = \cos c - \cos a \cos b $

On a aussi, si on veut faire joujou $ \cos\gamma = - \cos\alpha\,\cos\beta + \sin\alpha\,\sin\beta\,\cos c $

Effectivement, lorsque le rayon de courbure tend vers l'infini, i.e., abc->0, on retombe sur AlKashi avec un DL. ($ \sin a = a + o(a^2), \cos a = 1 - a^2/2 + o(a^2). $)
pour trouver $ ab\cos \gamma=-\frac{c^2}{2}+\frac{a^2}{2}+\frac{b^2}{2} $

Note : on peut meme s'amuser a le montrer (et c'est vrai, mais pas amusant du tout...) en geom hyperbolique, avec des pseudospheres (et les sin deviennent des sinh), et c'est vrai aussi en geometrie non euclidienne ou des trucs chelous, il me semble..
Lycée Masséna (Pcsi-PC*) -- École polytechnique (X15) -- PhD Student (Japon, Astrophysique) -- Ingé (spatial)

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