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/sci/ - Science & Math

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[ERROR] No.3780359 [Reply] [Original]

hello, i'm doing a practice review question and i'm stumped by what the answer should look like:

We know that sin^2(x)=(1-cos(2x))/2 and cos^2(x)=cos(x)^2=(1+cos(2x))/2. Use these formulas to find a formula for cos(2x)^2 in terms of cos(4x)

Thanks in advance :)

>> No.3780375

cos(x)^2=(1+cos(2x))/2

cos(2x)^2=(1+cos(4x))/2 = 1/2 + cos(4x)/2

Why did you even have to ask?

>> No.3780374

<span class="math"> (cos4x)/2 + 0.5 [/spoiler]

>> No.3780381

>>3780375
>>3780374

Im an idiot. thanks guys.

>> No.3780390
File: 247 KB, 401x332, zh4.png [View same] [iqdb] [saucenao] [google]
[ERROR]

>>3780381
no problem, hun.

>> No.3780406

The answer is
2 + (cos4x) / 3

>> No.3780413
File: 10 KB, 247x247, C1_dup.jpg [View same] [iqdb] [saucenao] [google]
[ERROR]

>>3780406
>2011
>be massive faggot

>> No.3780416

The answer is 0

>> No.3780421
File: 213 KB, 250x250, ace_hump.gif [View same] [iqdb] [saucenao] [google]
[ERROR]

>>3780413
Just helping another poster with his homework, fuzz-buddy! If you ever need any help with any, just post a homework thread. I'll be there in a jiffy!

>> No.3780443
File: 233 KB, 474x356, 01298436110.png [View same] [iqdb] [saucenao] [google]
[ERROR]

>>3780421
...with the wrong answer again?

>> No.3780502

>>3780421
You realize homework threads are against the rules of /sci/ right? Your contributing to rule breaking.

>> No.3780506
File: 59 KB, 755x308, grammarnaziyouryoure.jpg [View same] [iqdb] [saucenao] [google]
[ERROR]

>>3780502

>> No.3780511

>>3780443
>someone gets an answer wrong
>call them a faggot
You should think about a career in teaching, EK. :)

>> No.3780514
File: 254 KB, 458x358, 0126394.png [View same] [iqdb] [saucenao] [google]
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>>3780511
hehehheh

>> No.3780525

>>3780506
I can't speak for everyone but I often get caught up in an online conversation that I just type as I "hear" words in my head. So the first spelling that sounds phonetically correct, gets typed. It doesn't mean I don't know the difference or when to use either spelling. If I was typing it in a less conversational atmosphere, I wouldn't make the mistake. But when you're talking you don't think about the spelling, similarly when you're typing conversationally.

>> No.3780535

testing

>> No.3780539

>>3780525
i actually do the same thing. I think most people do. i only meant the image half-heartedly.

>> No.3780551 [DELETED] 

O MY FUCKING GOD OF CUNTS I CAN FINALLY POST!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

5 LONG MONTHS IT HAS BEEN 4CHAN!!!!!!!!!!!!

>> No.3780556
File: 7 KB, 211x175, 4colourtheoremtroll.png [View same] [iqdb] [saucenao] [google]
[ERROR]

>>3780551
reported

>> No.3780608
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>>3780556
oh shit!

>> No.3780610

>>3780608
Now he's gonna an hero just because of you.
Feel bad about it.

>> No.3780624

I can't help but feel a bit sad when I see stupid memes being spammed on sci...

>> No.3780625
File: 255 KB, 438x357, 01278434.png [View same] [iqdb] [saucenao] [google]
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>>3780610
lol, i actually think he deleted his post because he thought i was serious about the 'reported'
if its deleted, mods cant ban it right?

>> No.3780627

>>3780625
>not liking memes

Have you considered leaving 4chan?

>> No.3780631

>>3780625
You're a mod. You must know it.