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Hello, if someone could help with these two questions from my class MCV4UI, that would be great! Please explain so I understand :p

1. Given two perpendicular vectors a and b in R3. Show using component form that for any scalar k∈R, k≠0, that a is perpendicular to kb.

For this... I could prove using dot product like ...

a*bcosx = 0

a*bcos90 = 0

since cos90 = 0, a*b*0 will always be 0, and we know that if the dot product = 0, they are perpendicular. I just wasn`t sure how to prove it in component form.

2. If a = 2i -5j +k, b = 3i +2j -4k, c = 7i -j +2k, express the vector h = 68i - 34j +23k as a linear combination of a, b, c.

Thank you very much!

Hello, if someone could help with these two questions from my class MCV4UI, that would be great! Please explain so I understand :p

1. Given two perpendicular vectors a and b in R3. Show using component form that for any scalar k∈R, k≠0, that a is perpendicular to kb.

For this... I could prove using dot product like ...

a*bcosx = 0

a*bcos90 = 0

since cos90 = 0, a*b*0 will always be 0, and we know that if the dot product = 0, they are perpendicular. I just wasn`t sure how to prove it in component form.

2. If a = 2i -5j +k, b = 3i +2j -4k, c = 7i -j +2k, express the vector h = 68i - 34j +23k as a linear combination of a, b, c.

Thank you very much!

When should I use one and not the other? We just started a new unit in math *-* thank you for the help!

Hey!! So I thought I had these two figured out but apparently... no :p

A) 3^x+2 = 5(2.6)^x

I thought to do x+2log3 = xlog5 + log2.6, then just factor out the x and divide the logs but it didn't work and I got an answer of ... 1.49 when the correct answer is -4.11

B) 7^x-5 = (2)(3)^2x+1

For this one... I checked my notes and it was how I did it how I described up there ^ Maybe someone could just check this one to see what I did wrong because I believe I did it right.

7^x-5 = (2)(3)^2x+1

(x-5)log7 = (2x+1)log2 + log3

xlog7 - 5log7 = 2xlog2 + log2 + log3

xlog7 - 2xlog2 = log2 + log3 + 5log7

x(log7 -2log2) = log2 + log3 + 5log7

x = [log2 + log3 + log7^5]/[log7 - log2^2]

and I get... 20.58

Actual answer is -45.84

Thanks for the help everyone!!

Hey! I'm just doing a review for a math test tomorrow and there are like 5 questions I had no idea how to do! I already checked my notes but it wasn't covered.

a) logx = [log25 - log7]/3log5

I think my teacher said this was a calculator question? But I couldn't get it to work on mine :s I got the one after it though which was similar though...

b) 8000 = 410(1.07)^x

I'm not sure... set a base? Ehh... divide 8000/410? No idea even where to start ;-;

c) [(5^2x)(25^3x-1)] / (1/125)^x-7 = 625^-x+3

For this, I was thinking of getting a base of log 5 and simplifying it, but then I didn't know what to do after.

Thanks for all the help, guys and gals!

Hi there! I have an assignment due tomorrow for math and I'm stuck on the last question. It looks like this:

(2x-1)/[(x+1)(3x+2)] = A/(x+1) + B/(3x+2)

I have to solve for the two unknowns; A and B. The first thing that I did was I isolated A.

What I got in the end was:

A = [(2x -1) -B(x +1)]/(3x +2)

Then I simplified the original equation just so I wouldn't have a fraction in a fraction to deal with and I got this:

A = (2x - 1)/[(x+1)(3x+2)]

I substituted A = [(2x -1) -B(x +1)]/(3x +2) into A = (2x - 1)/[(x+1)(3x+2)] -B so it looks like..

[(2x -1) -B(x +1)]/(3x +2) = (2x - 1)/[(x+1)(3x+2)] - B

Now I'm a little bit stuck on what to do next! I have 2 B terms and it's hard to get them together. Help, please? Tell me if I've done this all wrong so far haha. My teacher said there was an algebraic way and a trial and error way and trial and error sounds too tiresome to do. Thank you!

I'm going to grade 10. I'm thinking things like, A Levels? GCSE? Thanks :3

figueira da fome?

C'est pour la classe de français! :3 It's due tomorrow and I forgot to ask my teacher to edit this. Hehh... :)

Ricardo était très nerveux pour le prèmier présentation de la pièce. Il était se faire du mouron et tourner en rond cercle. J’ai crie, ‘arrête!’. Il a regardé à moi. J’ai parlé lui imaginer le public dans sous-vêtements. Il a regardé a moi encore. J’ai parlé lui, ‘avoir confiance en moi’.

La pièce était un grand success. Ricardo dit tout ce role juste. Le public a adore lui. Il a remercié moi et a donne moi un stylo fait des plumes. Il dit William Shakespeare a le donné à kui après la pièce.

Je sais j’ai joué avec le passé. Je ne suis pas désolé.

A more specific map would be of North America/Canada but a world map is fine too.

I'm in grade nine french. We had to write a children's story about the environment. I have the english version then the french version. It's pretty simple, but I know I messed up with a bunch of grammar. Some things I had no idea how to say, like 'behind the tree'. And I also know I forgot quite a bit of accents, sorry. I was just being lazy :b

The Happy Wolf

Le Loup Content

The wolf was happy.

Le loup était content.

The forest was quiet, he had food and his friends were with him.

La foret était calme, il avait nourriture et ses amis soient avec lui.

But one day, he was walking...

Mais un jour, il était marche...

and he walked past an old tree stump.

et il marché passé une vieille souche d'arbre.

He looked up and saw that it was not only one.

Il regardé haut et vu qu'il n'était pas la derniere.

Behind this tree, was a clear field of newly-cut tree stumps.

Derriere l'arbre etait un champ de arbres qui etais coupe.

The wolf was not happy.

Le loup n'était pas content.

He said, "I will not do nothing. It's time for action."

Il écrier, "je ne sera pas faire rien. C'est temps pour action!

So the wolf ran and ran and ran and ran,

Ainsi le loup couru et couru et couru et couru,

before he got to the beaver who was cutting down the trees.

avant il arrive a la maison de castor qui était de coupe l'arbres.

He said politely, "excuse me sir, but why are you cutting down the trees? The animals in the forest need them to survive."

Il dit poliment, "excusez-moi monsieur, mais pourquoi vous etes coupe l'arbres? Les animaux dans la foret besoin l'arbres a habite."

The beaver said. "But we are animals from the forest too. We need the trees to make our homes."

Le castor dit, "mais nous sont animaux de la foret aussi. Nous besoin l'arbes a faire notra maisons."

The wolf thought. He thought and thought and thought and thought but came up with no solution.

Le loup penser. Il pense et pense et pense et pense mais il a non idee.

Finally, the beaver spoke, "I think instead of cutting new trees, we can use some old trees that had fallen down already..."

Finalement, le castor dit, "je pense nous pouvoir coupe arbres vieux au lieu de coupe l'arbres nouveaux.

The wolf liked the idea.

Le loup aime la idee beaucoup.

"Me and my friends could also plant new tree seeds for the future beavers and animals of the forest."

"Mes amies et moi pouvoir planter semences nouvelle pour le castor futur et les animaux de la foret."

The wolf and the beaver agreed to the plan. The wolf ran back to tell his friends.

Le loup et le castor convenues. Le loup couru retour a dire ses amis.

One year later, and a new field of tree saplings are growing in the field.

Un annee passe, et le champ a arbre jeune.

The wolf was happy again.

Le loup etais content encore.

Now I can't type my password at the login page.

Help?

I have a receipt and I can scan it. Is there a specific e-mail that I should send this to?

I know I have wireless internet, because my sister got it hooked up to her iPod Touch.

Well, I just bought a laptop (HP dv6t) and I can't figure it out.

I went to a wizard-type thing and it couldn't connect to my network.

Help, please? : )

Can't choose. :|

http://www.hollisterco.ca/webapp/wcs/stores/servle...

I have the Action Plan for Clean Water already from the Environmental Canada website. Can anyone give me more information about what they are doing? I'm writing an essay about water pollution.

Also, what other factors do industries have to not get rid of chemicals properly other than the cost?

Thank you : )

"It only takes one teaspoon of mercury to contaminate a twenty-acre lake."

I'm doing something on industrial water pollution.

What reasons do they have? I'm writing an essay, and like, I don't get why they're pouring it into rivers. Sure, it's more convenient to just wash it away. Isn't there anything else they could do to that waste?

So I'm a litter stuck on what to do after a step. I don't expand the brackets, but if you could show me that way too, that would be great.

[subject = y]

w = a(mx - by)

w/a = mx - by

w/a - mx = by

so... what do i do after that? i have no idea :S

my friend divided something by something then cancelled, if that helps.

here's another one:

[subject = b]

mp - wx = 3(tb + c)

mp - wx/ 3 = tb +c

mp - wx/ 3 - x = tb

and yeah ... i get stuck again...

am i even doing this right? d:

thank you for the help. : )

oh, and one more quick question -

when you're rearranging, do you follow bedmas or bedmas backwards?

I've been searching all over, and it's uggh. I know the FOIL thing, but that's pretty much all, because my sister taught me. My teacher didn't exactly show us how, and my sister has now forgotten. My mom and dad suck at algebra, and it's almost 11, so friends are probably sleeping.

Help please? and explain , because it's not that helpful to me if you just answer the question. I'll just get stuck on the next one.

So this is the question -

(11x^2 +6x - 2) - (5x^2 + 4x + 8)

Oh and after the minus sign, the question in the parenthesis gets like, switched right? So the +8 would become -8? Sorry, I'm new to this ! Thank you guys for the help !