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
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
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)
It might help to write the 1 in the numerator as sin squared(x/2) + cos squared(x/2). This makes the numerator a trinomial square and you get cancellation with the denominator.
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 ruclips.net/video/z6W856M3Fpw/видео.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
I=int((x^-2-cos(x))/(1/x+sin(x))^2)dx t=sin(x)+1/x dt=(cos(x)-x^-2)dx I=int(-t^-2)dt I=1/t+C I=x/(1+xsin(x))+C
an interesting integral
an interesting integral
I got e^x(1+cos x)/sin x + c
@@Mediterranean81 you may verify the result by taking the derivative wrpt x to see whether it = the integrand
@seegeeaye yeah i checked
an interesting integral
an interesting integral
an interesting integral
an interesting integral
Integration by parts
What is the name of the technique you used?
@@محمدالزيداوي-ه3ت my own methods,substitution without U, By Parts without U and dV
Buteful
an interesting integral
Thanks for an other video master
an interesting integral
an interesting integral
an interesting integral
an interesting integral
It might help to write the 1 in the numerator as sin squared(x/2) + cos squared(x/2). This makes the numerator a trinomial square and you get cancellation with the denominator.
Thanks for an other video.
That's very good master.
Thanks for an other video master.
(u/v)'=(u'v-uv')/v^2 v=x+e^x v'=1+e^x u'(x+e^x)-u(1+e^x)=(x-1)e^x u=-x u'=-1 I=-x/(x+e^x)+C
hello sir l like your way of teaching
wow.
From Iran Hello and Thanks
I would use integration by parts twice