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Seegee Aye
Приєднався 21 вер 2021
Відео
a short way to solve the equation
Переглядів 504 години тому
using nth roots of a unit to solve an equation
an interesting integral question
Переглядів 114День тому
nice methods to solve an interesting integral question
a quick way to solve a quintic euqation
Переглядів 35День тому
a quiick way to solve a quintic equation
I found the same result, by using directly the fact that x^(1/x) is equal to e^(ln(x)/x), and that e^(ln(x)/x) - 1 is equivalent at ln(x)/x when x approaches infinity, since e^(x) - 1 is the same as x, when x approaches 0. Then I got (ln(x)/x)^(1/ln(x)), after that I introduced the exponential and ln functions ( a^(b) = e^(b×ln(a)) ), to finally get e^(-1).
@@fahdfarachi6232 excellent
Your math topics are very wonderful and we are very excited about how they will be solved, but your use of the paper and raising and lowering it interrupts our chain of thought and confuses us, so I hope that you use one space that accommodates the screen
I'll definitely try, thanks
Can I apply LH rule ( L'Hôpital ) 🙏
If the conditions are met
Another method over here could have been Binomial Expansion, that gives you the answer way quicker, in about 2 minutes if not less
Hi @seegeeaye this wrong. It should be lim "K" -> 0 NOT lim "X" ->0 then the final limit will be n. Otherwise if x->0 final limit is 1 .
But I have assumed, from the context, that P(x) is a polynomial.
It seems the limit as x->0 of x^x^...^x is 1 for an even number of x's and 0 for an odd number of x's.
(-3)^x If we keep x A= 2/2 Where (-3)^2 = 9 Then root 9 is 3 So x is 1
Since P(x+1) = P(x) + x, P(x) must be quadratic. Let P(x) = ax^2+bx+c. Again, P(1)=P(0) which means a+b+c = c which gives b=-a. So, P(x) = a(x^2-x) + c. Again, P(2) = P(1) + 1 = c+1. Thus, a(4-2) + c = 1+c which means 2a=1 or a = 1/2, So, P(x)=1/2(x^2-x) + c. I am assuming that P(x) is a polynomial. So, periodic functions are disallowed.
"Since P(x+1) = P(x) + x, P(x) must be quadratic" is not totally true. you have to assume that P il polynomial to say that. And that is exactly my point : you can add "cos(x/(2pi))" and it will be a valid solution.
Just like i^2 = -1 similarly, this problem needs ln(-1) x = ln(3) / ln(-3) = ln(3) / (ln(3) + ln(-1)) but -1 = e^(i pi) so ln(-1) = i pi Therefore, x = ln(3) / (ln(3) + i pi) and also ln(3) / (ln(3) + i pi + i 2 pi n) [ since e^(i 2 pi n) = 1, so ln(-1) = i pi + i 2 pi n for any integer n ]
Love your use of Euler's identity. A beautiful and simple argument which provides all the complex solutions to the problem, and moreover, also happens to be correct. Good job!
Much simpler !
Thanks for an other video master
Solution: e^x e^x f(x) = ∫ln(t)*dt = ∫ln(t)*1*dt = 2 2 ------------------------------------ Solution by partial integration: Partial integration can be derived from the product rule of differential calculus. The product rule of differential calculus states: (u*v)’ = u’*v+u*v’ |-u’*v ⟹ (u*v)’-u’*v = u*v’ ⟹ u*v’ = (u*v)’-u’*v |∫() ⟹ ∫u*v’*dx = u*v-∫u’*v*dx ------------------------------------ e^x e^x e^x f(x) = [ln(t)*t]-∫1/t*t*dt = x*e^x-2*ln(2)-[t] = x*e^x-2*ln(2)-(e^x-2) 2 2 2 f(x) = x*e^x-e^x+2-2*ln(2) Now is: ln(2) ln(2) ∫x*f(x)*dx = ∫{x²*e^x-x*e^x+[2-2*ln(2)]*x}*dx = 0 0 (1) Solution of the indefinite integral ∫x*e^x*dx: ∫x*e^x*dx = ------------------------------------ Solution by partial integration: Partial integration can be derived from the product rule of differential calculus. The product rule of differential calculus states: (u*v)’ = u’*v+u*v’ |-u’*v ⟹ (u*v)’-u’*v = u*v’ ⟹ u*v’ = (u*v)’-u’*v |∫() ⟹ ∫u*v’*dx = u*v-∫u’*v*dx ------------------------------------ = x*e^x-∫e^x*dx = x*e^x-e^x+C = e^x*(x-1)+C (2) Solution of the indefinite integral ∫x²*e^x*dx: ∫x²*e^x*dx = ∫x*(x*e^x)*dx = ------------------------------------ Solution by partial integration: Partial integration can be derived from the product rule of differential calculus. The product rule of differential calculus states: (u*v)’ = u’*v+u*v’ |-u’*v ⟹ (u*v)’-u’*v = u*v’ ⟹ u*v’ = (u*v)’-u’*v |∫() ⟹ ∫u*v’*dx = u*v-∫u’*v*dx Look at (1): ------------------------------------ = x*(x*e^x-e^x)-∫(x*e^x-e^x)*dx = e^x*(x²-x)-(x*e^x-e^x-e^x)+C = e^x*(x²-x)-(x-2)*e^x+C = e^x*(x²-2x+2)+C Now is: ln(2) ln(2) ∫x*f(x)*dx = ∫{x²*e^x-x*e^x+[2-2*ln(2)]*x}*dx = 0 0 ln(2) = [e^x*(x²-2x+2)-e^x*(x-1)+[2-2*ln(2)]/2*x²] 0 ln(2) = [e^x*(x²-3x+3)+[1-ln(2)]*x²] 0 = 2*[ln²(2)-3*ln(2)+3]+[1-ln(2)]*ln²(2)-3 = 2*ln²(2)-6*ln(2)+6+ln²(2)-ln³(2)-3 = -ln³(2)+3*ln²(2)-6*ln(2)+3 ≈ -0,0505
Very cool
Thanks for an other video master
Thanks for an other video master
This is the Weierstrass substitution.
Why not let e raised to the power of -x equal sine theta?
Yes you could. Then the integral becomes int cosθ cotθ dϑ from π/6 to π/2, and it will end up with the same answer. Compare which way is shorter.
Thanks for an other video master.
How did you factor a pi/2 on 2:33? I think you made too many mistakes
Also you may solve woth Feynman taknic
Wow, just now I realised you could use the d(cosx) notation for IBP 🤯🤯
see many of my other videos, this is a commonly practical way of writing, simplifing integrations
Great video
Rewrite as \int{\frac{e^{x}}{1+\cos{x}} dx} + \int{\frac{e^{x}\sin{x}}{1+\cos{x}} dx} Integrate by parts \int{\frac{e^{x}\sin{x}}{1+\cos{x}} dx} with u = \frac{\sin{x}}{1+\cos{x}} , dv = e^{x}dx and combine integrals
I see integration by parts here with u = ln(x)
τ
an interesting integral
π ln (2) / 2
Using kings rule would solve it a lot quicker 🙌
Wow I would never have thought of it this way! I split it into integrals between -π~0 and 0~π and it turns into (∫[-π, 0] (x + |x|)sinx dx + ∫[-π, 0] (x + |x|)sinx dx), and now since x in the first integral is always negative, you can write |x| as -x, and the same logic allows you to write |x| as x in the second integral. So you end up with ∫[-π, 0] (x - x)sinx dx + ∫[-π, 0] (x + x)sinx dx which is ∫[-π, 0] 0 · sinx dx + ∫[-π, 0] 2x · sinx dx = 0 + 2 · ∫[-π, 0] sin dx = 0 + 2π = 2π
Your writing is so wonderful.❤❤❤❤❤
Solution: ∫1/(5^x+1)*dx = ∫(5^x+1-5^x)/(5^x+1)*dx = ∫(5^x+1)/(5^x+1)*dx-∫5^x/(5^x+1)*dx = ∫dx-∫5^x/(5^x+1)*dx = x-∫e^[x*ln(5)]/{e^[x*ln(5)]+1}*dx = x-1/ln(5)*∫e^[x*ln(5)]/{e^[x*ln(5)]+1}*ln(5)*dx --------------------- Substitution: u = e^[x*ln(5)]+1 du = ln(5)*e^[x*ln(5)] --------------------- = x-1/ln(5)*∫1/u*du = x-1/ln(5)*ln|u|+C = x-1/ln(5)*ln|e^[x*ln(5)]+1|+C = x-1/ln(5)*ln|5^x+1|+C Checking the result by deriving: [x-1/ln(5)*ln|5^x+1|+C]’ = 1-1/ln(5)*1/(e^[x*ln(5)]+1)*e^[x*ln(5)]*ln(5) = 1-5^x/(5^x+1) = (5^x+1-5^x)/(5^x+1) = 1/(5^x+1) everything okay!
I would split the fractions. First lets work on ploynomial on denominator X^4=-1 X^2=+-i X^2=i => x1=√2/2(1+i) x2=-√2/2(1+i) X^2=-i => x3=√2/2(1-i) X4=-√2/2(i-i). Now x1*x3=1/2(1+1)=1 and x1+x3=√2 X2x4=1 and x2+x4=-√2 So x^4+1=(x^2+√2x+1)(x^2-√2x+1) (Ax+B)/(X^2+√2x+1)+(Cx+D)/(X^2-√2x+1)=X^2/(x^4+1) (Ax+B)(X^2-√2x+1)+(Cx+D)(X^2+√2x+1)=X^2 X=√2/2(1+i) => (D+C*√2/2(i+1))*(i+1+i+1)=+i D(2+2i)+2√2C*i=i D=0 C=1/2√2 Similarly then A=0 B=-1/2√2 => X^2/(x^4+1)=√2/4(1/x^2-√2x+1)-1/(x^2+√2x+1))=√2/4(1/((x-√2/2)^2+(√2/2)^2)-1/((x+√2/2)^2+(√2/2)^2)) Now all that is left is using the identity Arctan'(x/a)=a/(x^2+a^2) I missed an x on nunerator so we need to first make the top similar to derivative of denominator first by afdind and subtracting a number which will resilt in logarithm antiderivative and then the arcatngent formula
a good part of mathematic
Just take divide numerator and denominator by 5^x. You get integral of dx/5^x(1+1/5^x) Then you set u=1/5^x, du=ln(1/5)/5^x. dx Substitute into the equation 1/ln(1/5) × integral of du/1+u. And the answer is ln(1+1/5^x)/ln(1/5)
divede 5^x is to multiply 5^-x, the same
an interesting integral
14/11/2024
an interesting integral
Buteful 🎉🎉🎉
an interesting integral
mhm
Thanks, if the integral had no upper and lower limits, how would it be solved, Professor?
here is to answer your question ua-cam.com/video/z6W856M3Fpw/v-deo.html
Thanks for an other video master
Thanks
an interesting integral
an interesting integral
You amazing me with those internal half angles
an interesting integral
an interesting integral
Thanks for an other video master
an interesting integral
an interesting integral
I=int((xsec^2(x)+tan(x))/(1+xtan(x))^2)dx t=1+xtan(x) dt=(xsec^2(x)+tan(x))dx I=int(t^-2)dt I=-1/t+C I=-cos(x)/(cos(x)+xsin(x))+C
bro changed the problem on step 3 for no reason