Title: Openai/6936f996-e124-8004-a264-0b3da0e38976 - freem URL Source: https://freemwiki.com/index.php?mobileaction=toggle_view_mobile&title=Openai%2F6936f996-e124-8004-a264-0b3da0e38976 Markdown Content: _This conversation was exported from ChatGPT_[[1]](https://freemwiki.com/index.php?mobileaction=toggle_view_mobile&title=Openai%2F6936f996-e124-8004-a264-0b3da0e38976#cite_note-1) ## gpt-5-1-thinking[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=1 "Edit section: gpt-5-1-thinking") ### User: Can it be taken analytically?[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=2 "Edit section: User: Can it be taken analytically?") Can it be taken analytically? ### Assistant: Yes, it can be integrated in closed form.[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=3 "Edit section: Assistant: Yes, it can be integrated in closed form.") Yes, it can be integrated in closed form. ∫3x3−x2+2x−4x2−3x+2 dx=x2−3x+2(x2+134x+1018)+13516ln⁡ ⁣∣2x−3+2x2−3x+2∣+C.\int \frac{3x^{3}-x^{2}+2x-4}{\sqrt{x^{2}-3x+2}}\,dx = \sqrt{x^{2}-3x+2}\left(x^{2}+\frac{13}{4}x+\frac{101}{8}\right) +\frac{135}{16}\ln\!\left|2x-3+2\sqrt{x^{2}-3x+2}\right|+C.∫x2−3x+2​3x3−x2+2x−4​dx=x2−3x+2​(x2+413​x+8101​)+16135​ln​2x−3+2x2−3x+2​​+C. Sketch of how to get it: 1. Denote Q(x)=x2−3x+2Q(x)=x^{2}-3x+2Q(x)=x2−3x+2. Look for an antiderivative of the form Q(x)(Ax2+Bx+C)+KQ(x)\sqrt{Q(x)}(Ax^{2}+Bx+C)+\dfrac{K}{\sqrt{Q(x)}}Q(x)​(Ax2+Bx+C)+Q(x)​K​. 2. Differentiate this expression, collect terms over Q(x)\sqrt{Q(x)}Q(x)​, and match the resulting polynomial in the numerator with 3x3−x2+2x−43x^{3}-x^{2}+2x-43x3−x2+2x−4. Solving for A,B,C,KA,B,C,KA,B,C,K gives A=1, B=134, C=1018, K=13516A=1,\;B=\tfrac{13}{4},\;C=\tfrac{101}{8},\;K=\tfrac{135}{16}A=1,B=413​,C=8101​,K=16135​. 3. The remaining integral ∫dxx2−3x+2\displaystyle \int \frac{dx}{\sqrt{x^{2}-3x+2}}∫x2−3x+2​dx​ is handled by completing the square x2−3x+2=(x−32)2−(12)2x^{2}-3x+2=(x-\tfrac32)^2-(\tfrac12)^2x2−3x+2=(x−23​)2−(21​)2 and using ∫dxx2−a2=ln⁡∣x+x2−a2∣+C.\displaystyle \int \frac{dx}{\sqrt{x^{2}-a^{2}}} =\ln\left|x+\sqrt{x^{2}-a^{2}}\right|+C.∫x2−a2​dx​=ln​x+x2−a2​​+C. Combining gives the result above. ### User: So, what is the analytical answer, and then calculate the answer from the analytical answer to get number.[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=4 "Edit section: User: So, what is the analytical answer, and then calculate the answer from the analytical answer to get number.") So, what is the analytical answer, and then calculate the answer from the analytical answer to get number. ### Assistant: Let’s write the integral clearly:[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=5 "Edit section: Assistant: Let’s write the integral clearly:") Let’s write the integral clearly: ∫3x3−x2+2x−4x2−3x+2 dx\int \frac{3x^{3}-x^{2}+2x-4}{\sqrt{x^{2}-3x+2}}\,dx∫x2−3x+2​3x3−x2+2x−4​dx ##### 1. Analytical antiderivative[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=6 "Edit section: 1. Analytical antiderivative") One antiderivative is F(x)=x2−3x+2(x2+134x+1018)+13516ln⁡ ⁣∣2x−3+2x2−3x+2∣+C.F(x)=\sqrt{x^{2}-3x+2}\left(x^{2}+\frac{13}{4}x+\frac{101}{8}\right) +\frac{135}{16}\ln\!\left|2x-3+2\sqrt{x^{2}-3x+2}\right|+C.F(x)=x2−3x+2​(x2+413​x+8101​)+16135​ln​2x−3+2x2−3x+2​​+C. (Differentiating F(x)F(x)F(x) gives exactly the integrand.) ##### 2. Definite integral (taking limits[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=7 "Edit section: 2. Definite integral (taking limits") 0 0 to 1 1) Your picture shows a lower limit 000; the natural upper limit, given the domain of (x−1)(x−2)\sqrt{(x-1)(x-2)}(x−1)(x−2)​, is 111. Assuming the integral is ∫013x3−x2+2x−4x2−3x+2 dx,\int_{0}^{1} \frac{3x^{3}-x^{2}+2x-4}{\sqrt{x^{2}-3x+2}}\,dx,∫01​x2−3x+2​3x3−x2+2x−4​dx, we plug into F(x)F(x)F(x): ∫013x3−x2+2x−4x2−3x+2 dx=F(1)−F(0)=−10182−13516ln⁡ ⁣(3−22).\int_{0}^{1} \frac{3x^{3}-x^{2}+2x-4}{\sqrt{x^{2}-3x+2}}\,dx =F(1)-F(0) =-\frac{101}{8}\sqrt{2}-\frac{135}{16}\ln\!\bigl(3-2\sqrt{2}\bigr).∫01​x2−3x+2​3x3−x2+2x−4​dx=F(1)−F(0)=−8101​2​−16135​ln(3−22​). Numerically (to 10 digits): ∫01⋯dx≈−2.981266944.\int_{0}^{1} \cdots dx \approx -2.981266944.∫01​⋯dx≈−2.981266944. Confidence this is correct: ~99% (symbolically checked by differentiating the antiderivative and by direct numeric integration). ### User: I did not ask numerically integrate.[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=8 "Edit section: User: I did not ask numerically integrate.") I did not ask numerically integrate. Calculate from your analytical answer to definite integral. ### Assistant: Let me assume the definite integral is[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=9 "Edit section: Assistant: Let me assume the definite integral is") Let me assume the definite integral is I=∫013x3−x2+2x−4x2−3x+2 dx,I=\int_{0}^{1} \frac{3x^{3}-x^{2}+2x-4}{\sqrt{x^{2}-3x+2}}\,dx ,I=∫01​x2−3x+2​3x3−x2+2x−4​dx, since x2−3x+2=(x−1)(x−2)\sqrt{x^{2}-3x+2}=\sqrt{(x-1)(x-2)}x2−3x+2​=(x−1)(x−2)​ is real on [0,1][0,1][0,1]. ##### 1. Analytical evaluation[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=10 "Edit section: 1. Analytical evaluation") An antiderivative is F(x)=x2−3x+2(x2+134x+1018)+13516ln⁡ ⁣(2x−3+2x2−3x+2).F(x)=\sqrt{x^{2}-3x+2}\left(x^{2}+\frac{13}{4}x+\frac{101}{8}\right) +\frac{135}{16}\ln\!\bigl(2x-3+2\sqrt{x^{2}-3x+2}\bigr).F(x)=x2−3x+2​(x2+413​x+8101​)+16135​ln(2x−3+2x2−3x+2​). So I=F(1)−F(0).I = F(1)-F(0).I=F(1)−F(0). * At x=1x=1x=1: 1−3+2=0\sqrt{1-3+2}=01−3+2​=0, and the log term is ln⁡(0)\ln(0)ln(0), which → −∞-\infty−∞, but multiplied by 0 from the prefactor in the derivation the limit is finite; easier is to use the symbolic simplification already done, which gives the exact result below. Carrying out the algebra (which SymPy also confirms) gives I=−10182−13516ln⁡(3−22).I=-\frac{101}{8}\sqrt{2}-\frac{135}{16}\ln(3-2\sqrt{2}).I=−8101​2​−16135​ln(3−22​). Using (3−22)(3+22)=1⇒ln⁡(3−22)=−ln⁡(3+22)(3-2\sqrt{2})(3+2\sqrt{2})=1\Rightarrow \ln(3-2\sqrt{2})=-\ln(3+2\sqrt{2})(3−22​)(3+22​)=1⇒ln(3−22​)=−ln(3+22​), a slightly nicer exact form is I=−10182+13516ln⁡(3+22) .\boxed{\,I=-\frac{101}{8}\sqrt{2}+\frac{135}{16}\ln(3+2\sqrt{2})\,}.I=−8101​2​+16135​ln(3+22​)​. That is the analytical answer. ##### 2. Numerical value from this formula (no numerical integration)[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=11 "Edit section: 2. Numerical value from this formula (no numerical integration)") Use 2≈1.4142135623730950,ln⁡(3+22)≈1.7627471740390861.\sqrt{2}\approx 1.4142135623730950,\qquad \ln(3+2\sqrt{2})\approx 1.7627471740390861.2​≈1.4142135623730950,ln(3+22​)≈1.7627471740390861. Compute the two terms: −10182≈−12.625⋅1.4142135623730950≈−17.854446224960325,-\frac{101}{8}\sqrt{2} \approx -12.625\cdot 1.4142135623730950 \approx -17.854446224960325,−8101​2​≈−12.625⋅1.4142135623730950≈−17.854446224960325, 13516ln⁡(3+22)=8.4375⋅1.7627471740390861≈14.873179280954789.\frac{135}{16}\ln(3+2\sqrt{2}) =8.4375\cdot 1.7627471740390861 \approx 14.873179280954789.16135​ln(3+22​)=8.4375⋅1.7627471740390861≈14.873179280954789. Add them: I≈−17.854446224960325+14.873179280954789≈−2.981266944005536.I \approx -17.854446224960325 +14.873179280954789 \approx -2.981266944005536.I≈−17.854446224960325+14.873179280954789≈−2.981266944005536. So I≈−2.9812669440\boxed{I\approx -2.9812669440}I≈−2.9812669440​ (from the closed-form expression, accuracy ≳10 significant digits). ## References[edit](https://freemwiki.com/index.php?title=Openai/6936f996-e124-8004-a264-0b3da0e38976&action=edit§ion=12 "Edit section: References") 1. [↑](https://freemwiki.com/index.php?mobileaction=toggle_view_mobile&title=Openai%2F6936f996-e124-8004-a264-0b3da0e38976#cite_ref-1 "Jump up")["Analytical integration solution"](https://chatgpt.com/share/6936f996-e124-8004-a264-0b3da0e38976). ChatGPT. Retrieved 2025-12-09.