e^x=(x^2)-2

File: 89-big.gif (108KB, 358x515px) Image search: [Google]

108KB, 358x515px

>>8618130
F2 -> Solve

>>8618137
That doesn't help very much

There is no closed form solution, I believe x would have to be transcendental.
Also, here's the answer if you need it:
https://www.wolframalpha.com/input/?i=solve+e%5Ex%3Dx%5E2-2+for+x

Couldnt you just take ln on both sides to get e off?

https://en.wikipedia.org/wiki/Lambert_W_function

>>8618130
that image makes absolutely no sense to me

f(x) = e^x - x^2 + 2

f(-1) = 1.36...
f(-2) = -1.86...
f(0) = 3
f(1) = 3.78...
f(2) = 5.38...

Well it's between -1 and -2.

e^x = x^2 - 2
1 + x + x^2 /2 + x^3 /3! + ... = x^2 - 2
3 + x - x^2 /2 + x^3 /3! + ... = 0
aaand I can't go anywhere from here

use newtons method

make a guess for about where they'll be equal.

say x_0 = -1.5.

let f(x) = e^x - x^2 + 2 = 0

the derivative will be

f'(x) = e^x - 2x = 0

now we can get a better approximation by computing:

x_1 = -1.5 - [f(-1.5)/f'(-1.5)]

this new better approximation, x_1, is about −1.5181297346 if i calculate it right

you can then repeat this, using x_1 instead of x_0, to find x_2, an even better estimation.

>>8618862
thank you

peace of cake
[math]\frac{d}{dx}e^{x}=\frac{d}{dx}(x^{2}-2)[/math]
[math]\frac{d}{dx}e^{x}=\frac{d}{dx}2x[/math]
[math]e^{x}=2[/math]
[math]x=ln\;2[/math]

>>8618943
I am going to give you 5 minutes for you to tell me why what you just wrote is completely fucking wrong.

If you see nothing wrong or can't find it then please go back to /g/. Those guys are closer to your level.

>>8618964
oh right, i misspelled piece

>>8619003
Back to /g/.

x is a constant, not an variable.

so if you differentiate e^x=(x^2)-2 where x is a constant, you get 0 = 0, which is not useful.

checkmate :)

i feel like this involves the W "function"

>>8618616
>>8619635
You guys are idiots.

>>8619678
why?

File: 1479561070267.png (187KB, 500x323px) Image search: [Google]

187KB, 500x323px

>>8618943
>d/dx e^x = e^x

>>8620432
WOW YOU'RE RIGHT, THAT'S WHAT'S WRONG ABOUT THIS COMPUTATION!

>>8618943
How to solve 2x = x^2 (by your logic)

[math]\frac{d}{dx}2x= \frac{d}{dx}x^2[/math]
[math]\frac{d}{dx}2= \frac{d}{dx}2x[/math]
[math]0= 2[/math]

Then, because contradiction implies everything, x takes on every possible value.

File: 1469811543721.png (257KB, 591x716px) Image search: [Google]

257KB, 591x716px

>>8620465
stop being rude I just started taking calc 1 at community college

I just wanted to fit in

>>8620500
get out

File: 1471047033929.jpg (71KB, 735x599px) Image search: [Google]

71KB, 735x599px

>>8620531
no

>>8620500
you learned power rule this quickly in the semester?

File: 6d33fe0ce459708fb1430c4bc42c4f28574fdea9cf8f942827ee4707cffd2041.png (294KB, 737x450px) Image search: [Google]

294KB, 737x450px

>>8618130
What the fuck is that pic, comrade?

>>8620554
>started with simple differentiation
>went over rules, including power rule in first weeks

should we have taken longer or something?