How Gauss solved the integral of e^(-x^2) from 0 to infinity

Here's how Gauss solved the Gaussian Integral, i.e. the integral of e^(-x^2) from 0 to infinity, by using the polar coordinate. This is a must-know integral for your multi-variable calculus class! To see how Laplace solved the Gaussian integral, click here: • how Laplace solved the...
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Пікірлер: 30

  • @bprpcalculusbasics
    @bprpcalculusbasics8 ай бұрын

    To see how Laplace solved the Gaussian integral, click here: kzread.info/dash/bejne/pneEs7WoktSsmJc.html

  • @Ninja20704
    @Ninja20704 Жыл бұрын

    Very cool integral. Seeing this helps me to understand why the function for the normal distribution curve has the 1/sqrt(2*pi) in the front.

  • @breakoff2381
    @breakoff2381 Жыл бұрын

    I am obsessed with this integral and the gamma function

  • @dumbass4385

    @dumbass4385

    Ай бұрын

    Same

  • @Jacobiano_
    @Jacobiano_ Жыл бұрын

    Can't believe a semester ago I mastered this and now I completely forgot how to solve this. Thanks for showing me I have to practice more.

  • @johns.7752
    @johns.7752 Жыл бұрын

    I find it interesting that the jacobian matrix you end up getting is just the rotation matrix in R2 multiplied on the right by the column vector [1 ; r]. There must be an explicit reason for this beyond "the math just works out that way."

  • @allmight801
    @allmight80110 ай бұрын

    He's truly the best

  • @u36reck63
    @u36reck63 Жыл бұрын

    beautiful

  • @jaygatsby9975
    @jaygatsby9975 Жыл бұрын

    brilliant

  • @IHateTheSaiyanMonkeys
    @IHateTheSaiyanMonkeysАй бұрын

    We get this problem in Class 12th Cengage Dpp

  • @anupamamehra6068
    @anupamamehra6068 Жыл бұрын

    too good

  • @user-ks5ci6bs6x
    @user-ks5ci6bs6x Жыл бұрын

    The region of this double integral is a circle ,the bound for theta should be integrating from 0 to 2 pi , isn’t?

  • @bprpcalculusbasics

    @bprpcalculusbasics

    Жыл бұрын

    Oh bc we are only integrating it from x=0 to inf. We are in the first quadrant.

  • @JoseEliasOD
    @JoseEliasOD Жыл бұрын

    Can you explain what the jacobian is and prove the formula to calculate it?

  • @user-ks5ci6bs6x

    @user-ks5ci6bs6x

    Жыл бұрын

    that proof is cool but beyond the scope of undergraduate

  • @ShanBojack

    @ShanBojack

    Жыл бұрын

    ​@@user-ks5ci6bs6x true but an explanation would be nice

  • @oke5403

    @oke5403

    5 ай бұрын

    ​​@@user-ks5ci6bs6xreally? in poland i had it first in analysis 3(we don't have calc curses specifically but analysis is mostly the same as calc in america pretty sure) and then the use like demonstrated here in analysis 4. both times with proofs.

  • @lucasfranco1758

    @lucasfranco1758

    2 ай бұрын

    if I remember correctly, there's a great video on Khan academy about this subject

  • @FEg-xw6jq
    @FEg-xw6jq10 ай бұрын

    I neeb to know the reson why the two therm integral combine togethe?

  • @Abedchess

    @Abedchess

    6 ай бұрын

    Integral of e^(-x^2) dx from 0 to infinity is just a number. Remember, it is a definite integral. Integral of e^(-y^2) dy from 0 to infinity is also another number, which is the same number as before. If you let I = Integral of e^(-x^2) dx, (Note, I is now a number also. I'm lazy to write out the limits, but just assume the limits are all 0 to infinity) and since you know Integral of e^(-x^2) dx = Integral of e^(-y^2) dy Thats why I^2 = (Integral of e^(-x^2) dx) (Integral of e^(-y^2) dy) = double integral e^-(x^2+y^2) dx dy The reason for this procedure is because, there is a neat trick for integrating anything containing "x^2+y^2". The trick is changing to polar coordinates. As for why integral f(x) dx integral g(y) dy = double integral f(x) g(y) dx dy. Its because of the property of summation

  • @FEg-xw6jq
    @FEg-xw6jq10 ай бұрын

    Sir, I don't understand the point of intigral multiplication? Plese shwo me

  • @clolulu2393
    @clolulu239311 ай бұрын

    how did u know that it is in the first quadrant?

  • @advaykumar9726

    @advaykumar9726

    7 ай бұрын

    Both x and y lies from 0 to infinity therefore both are positive Hence it lies in first quadrant

  • @user-ks5ci6bs6x
    @user-ks5ci6bs6x Жыл бұрын

    Why integrate theda from 0 to pi/2 but not 2pi?

  • @__fahim.__123

    @__fahim.__123

    8 ай бұрын

    Ig its bcoz we jus only considered the first quadrant in the circle when we changed it into polar form like more than pi/2 its juss a matter of perspective

  • @mitcigamer4289

    @mitcigamer4289

    3 ай бұрын

    the original bounds of both x and y were positive and hence we're only in the first quadrant. Hence the theta can only be 0 to pi/2

  • @technicallightingfriend4247
    @technicallightingfriend424711 ай бұрын

    -infinity to infinity π

  • @caden5426
    @caden5426 Жыл бұрын

    First

  • @tabridgazco.6404
    @tabridgazco.64044 ай бұрын

    That is not correct manner , because the y= e^-x^2 is not equal the e^-y^2