Are You Ready to Challenge Your Integral Solving Skills?

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SUMMARY

This discussion focuses on solving indefinite integrals, specifically the integrals of sqrt(tan(x)) and I = ∫(dx/(2+sin(x))). Participants share various substitution techniques, including u = tan(x/2) and u^2 = tan(x), to simplify these integrals. The use of integration by parts and partial fractions is also emphasized as effective strategies. The conversation highlights the challenges faced by learners in calculus and the collaborative effort to provide guidance and hints for solving complex integrals.

PREREQUISITES
  • Understanding of integral calculus concepts
  • Familiarity with substitution methods in integration
  • Knowledge of integration techniques such as integration by parts and partial fractions
  • Basic proficiency in LaTeX for mathematical expressions
NEXT STEPS
  • Practice solving integrals using substitution methods, particularly u-substitution
  • Learn about integration by parts and its applications in solving complex integrals
  • Explore partial fraction decomposition for simplifying rational functions in integrals
  • Study hyperbolic substitutions and their use in integral calculus
USEFUL FOR

Students and self-learners in calculus, mathematics educators, and anyone looking to enhance their skills in solving indefinite integrals.

  • #271
Gib Z said:
Was that aimed at me or rocophysics? I know I stink :( Whats a wine?
It was aimed at you, I've already spoiled :p
 
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  • #272
How good are YOU ?

Here are some of my favourite integrals, ranging from beginners to just no.
Some of these have been posted before, most have not. Have fun.

Have fun and gl

Easier problems at the top, harder problems at the bottom. I really love all of these

Easy

I \, = \, \int {\frac{x}{e^x}} dx
I \, = \, \int_0^{\frac{\pi }{3n}} \tan \left( {nx} \right) dx
I \, = \, \int \frac{x^2+1}{x(x^2+3)} dx
I \, = \, 1+\int_{229}^{1234} (\sin(x)+\cos(x))^2+(\cos(x)-\sin(x))^2 \, dx
I \, = \, \int {\frac{1}{x\ln x}} dx
I \, = \, \int {\frac{{{e^x} + 1}}{{{e^x} - 1}}} dx
I \, = \, \int \frac{\sin(x)}{\sin(x)-1} dx
I \, = \, \int {2^{\ln(x)}} dx
I \, = \, \int {{e^{x + {e^x}}}} dx
I \, = \, \int_0^4 {\frac{\ln \left( x \right)}{\sqrt x}} dx
I \, = \, \int {{e^{\sqrt x }}} dx
I \, = \, \int \frac{1}{x^7-x} dx
I \, = \, \int\limits_0^4 {\frac{1}{{1 + \sqrt x }}} dx
I \, = \, \int \frac{\cos \left( x \right) - \sin \left( x \right)}{\sin \left( x \right) + \cos \left( x \right)} \, dx
I \, = \, \int \frac{\sin(x)\cos(x)}{\cos(x)^4-\sin(x)^4} \, dx
I \, = \, \int \frac{\sqrt{\sqrt{\ln(x)}+1}}{x} dx
I \, = \, \int \frac{1}{1+\sin\left( \frac{\pi}{6} \right)^x} dx
I \, = \, \int {\frac{1}{x \ln{{\left( x \right)}^n}}} dx
I \, = \, \int {\frac{{x{e^x}}}{{{{\left( {x + 1} \right)}^2}}}} dx
I \, = \, \int \frac{2010}{x(1+x^{2010})} dx

Find the area between the function f(x) and the x-axis when f(x)=\sqrt{a-\sqrt{x}}

Show that \int \left( {x + 3} \right) \left( {x - 1} \right)^5 dx \: equals \: \frac{1}{21}\left( {3x + 11} \right){{\left( {x - 1} \right)}^6} + C

Medium

I \, = \, \int \sin(\ln(x)) + \cos(\ln(x)) dx
I \, = \, \int {\left( {1 + 2{x^2}} \right){e^{{x^2}}}} \, dx
I \, = \, \int \frac{\ln(x)-1}{\ln(x)^2} \, dx
I \, = \, \int_{\pi}^{3\pi} \sin(x)\ln(x) - \frac{\cos(x)}{x} \, dx
I \, = \, \int \frac{1}{\ln(x)}+\ln(\ln(x)) \, dx
I \, = \, \int (x+3) \sqrt{e^x \cdot x} dx
I \, = \, \int \arccos(x) + \arcsin(x) dx
I \, = \, \int \frac{1}{\cos(x)} dx
I \, = \, \int \frac{4(\ln x)^2+1}{(\ln x)^{\frac 32}}\ dx
I \, = \, \int \frac{1}{\sqrt[3]{x}+x}\, dx
I \, = \, \int \frac{\sin(x)+\sin(3x)}{\cos(3x)+\cos(x)} \, dx
I \, = \, \int \frac{1}{\sqrt{x+x\sqrt{x}}} \, dx
I \, = \, \int \sin(101x)\cdot\sin(99x) \, dx
I \, = \, \int {\frac{{\sqrt {x + 1} - \sqrt {x - 1} }}{{\sqrt {x + 1} + \sqrt {x - 1} }}} \, dx
I \, = \, \int_0^1 \frac{x}{1+x}\sqrt{1-x^2}\ dx
I \, = \, \int \frac{1}{x^{a+1}+x} \, dx \; a>0
I \, = \, \int \frac{2^x \cdot 3^x}{9^x- 4^x} \, dx
I \, = \, \int \frac{1 + 2x^2}{x^5 \left( 1 + x^2 \right)^3} \, dx
I \, = \, \int \frac{1}{\sqrt{5x+3}-\sqrt{5x-2}} \, dx
I \, = \, \int \frac{\sqrt{x+\sqrt{x^2+1}}}{\sqrt{x^2+1}}
I \, = \, \int_1^e \frac{\ln x-1}{x^2-(\ln x)^2}dx
I \, = \, \int_{1}^{\sqrt{3}} x^{2x^2+1}+\ln(x^{2x^{2x^2+1}}) dx

The integral \; \int\limits_{\frac{\pi }{6}}^{\frac{\pi }{2}} {\sin {{\left( {2x} \right)}^3}\cos {{\left( {3x} \right)}^2} \, dx }
can be written as \; \left( \frac{a}{b} \right)^b where a and b are integers. Find \sqrt{a^b+b^a+1}

I \, = \, \int \frac{\left( x + 2 \right)^5}{\left( x + 7 \right)^2} \, dx
I \, = \, \int \frac{\sinh(x)+\cosh(x)}{\cosh(x)-\sinh(x)} \, dx
I \, = \, \int\limits_0^{\pi /2} {\sqrt {1 - 2\sin \left( {2x} \right) + 3\cos {{\left( x \right)}^2}} dx}
I \, = \, \int_{0}^{\pi/2} \ln(sec(x))
I \, = \, \int_{0}^{a} \frac{1}{\sqrt{x^2+a^2}} dx
I \, = \, \int \sqrt{ \sqrt{x+2\sqrt{2x+4}} + \sqrt{x-2\sqrt{2x+4}} } dx
I \, = \, \int \frac{ \left( 1 + x^2 \right) } { \left( 1 - x^2 \right) \sqrt{1 + x^4} } \, dx
I \, = \, \int \frac{ \sin(x) + \cos(x) }{e^x + 3 \cos(x) } \, dx
I \, = \, \int \sqrt{ \frac{k + x}{x} } \, dx
I \, = \, \int_{0}^{\infty} x^n \cdot e^{-x} \, dx
I \, = \, \int {\frac{x}{1+\cos(x)}} \, dx
I \, = \, \int {\frac{{{x^2} + 1}}{{{x^4} + 1}}} \, dx
I \, = \, \int\limits_{ - \pi }^\pi {\sqrt {1 + \cos \left( x \right)} } \, dx
I \, = \, \int e^{x/2} \cdot \left( \frac{2 - \sin \left( x \right) }{1 - \cos \left( x\right) } \right) \, dx
I \, = \, \int_{0}^{\infty} \frac{\{1-(x-1)e^x\}\ln(x)}{(1+e^x)^2} dx
I \, = \, \int\limits_0^{\ln \left( 2 \right)} {\sqrt {\frac{{{e^x} + 1}}{{{e^x} - 1}}} } \, dx
I \, = \, \int_{0}^{\infty} \frac{1}{ \left( x + \sqrt{1+x^2} \right)^{\phi}} \, dx \qquad \phi=\frac{1+\sqrt{5}}{2}
I \, = \, \int_0^{\infty} \frac{1}{(x^2+2)^3} \, dx
I \, = \, \int \sqrt{\frac{1}{\,\sin(x)+1}\,}\, dx
I \, = \, \int {\sqrt[3] {\tan \left( x \right)} } \, dx
I \, = \, \int_{0}^{\infty} \frac{x^{29}}{(5x^2+49)^{17}}\, dx \, = \, \frac{14!}{2 \cdot 5^{15} \cdot 49^2 \cdot 16! }\, dx
I \, = \, \int \left( \frac{\arctan(x)}{x-\arctan(x)} \right)^2 \, dx

"Fun"

I \, = \, \int_{1}^{\infty} \ln\left( \sqrt[X]{x} \right)^{2011} dx
I \, = \, \int_{0}^{2\pi} \frac{x \sin(x)}{1+\sin(x)^2} dx
I \, = \, \int_{0}^{2\pi} {\frac{1}{1+e^{\cos(x)}}} dx
I \, = \, \int_0^{\frac {\pi}{2}} \frac{(\sin x)^{\cos x}}{(\cos x)^{\sin x} + (\sin x)^{\cos x}} dx
I \, = \, \int_2^{4} \frac{\sqrt{\ln(9-x)}}{\sqrt{\ln(3+x)}+\sqrt{\ln(9-x)}} dx
I \, = \, \int_{-1}^{1} \arctan(e^x) dx
I \, = \, \int_{0}^{1} \ln(x)\cdot\ln(1-x) dx
I \, = \, \int_{-\pi/2}^{\pi/2} \frac{1}{1+2009^x} \cdot \frac{\sin(2010x)}{\sin(2010x)+\cos(2010x)} dx
I \, = \, \int \frac{1}{(x^2+1)^k} dx
I \, = \, \int_{0}^{\infty} \frac{x}{e^x-1} dx
I \, = \, \int_{0}^{a} \frac{1}{x+\sqrt{a^2-x^2}} dx \quad a>0
I \, = \, \int_{0}^{\infty} \frac{\ln{2x}}{x^2+9} dx
I \, = \, \int_{0}^{\pi/2} \ln(1-a \cos(x)) \, dx
I \, = \, \int_{-\infty}^{\infty} \sin(x^2)+\cos(x^2) dx
I \, = \, \int_{-\infty}^{\infty} \frac{x^a+x^b}{\ln(x)} dx \qquad (a,b)\forall >-1
I \, = \, \int_0^1 \frac{\ln(1+x^2)}{1+x^2} dx
I \, = \, \int_{0}^{\infty}\frac{1}{x^n+1} dx \quad n>1
I \, = \, \int_{0}^{\pi} \frac{1-\cos{(n\cdot x)}}{1-\cos(x)} dx \quad n\in\mathbb{N^+}
I \, = \, \int_{0}^{1} \ln(x) \cdot e^{-x} \cdot (1-x) dx
I \, = \, \int_{0}^{\infty} \ln\left( \frac{e^x+1}{e^x-1}\right) dx
I \, = \, \int_{0}^{\pi} \ln \left( 1 - 2\alpha \cos(x) + \alpha^2 \right) dx
I \, = \, \int_0^{\infty} \ln (1+e^{-ax} ) dx \quad a>0
I \, = \, \int_0^{\infty} 1 - x\sin\left( \frac{1}{x} \right) dx
I \, = \, \int_0^{\infty} \ln (1+e^{-ax} ) dx \quad a>0
I = \int_{0}^{\infty} \frac{{{e^{ - x}}\left( {1 - {e^{ - 6x}}} \right)}}{{x\left( {1 + {e^{ - 2x}} + {e^{ - 4x}} + {e^{ - 6x}} + {e^{ - 8x}}} \right)}}dx
I = \int\limits_0^1 {\frac{{\sin \left( {p\ln x} \right) \cdot \cos \left( {q\ln x} \right)}}{{\ln x}}}dx
I \, = \, \int_{a}^{\infty} \frac{1}{x^{n+1} \cdot \sqrt{x^2-a^2}} \, dx n \in \mathbb{N}^{+} \; , \; a>0
I \, = \, \int_{a}^{\infty} \frac{x^{-p}}{1+x} \, dx
I \, = \, \int_{ - \infty }^{\infty} \frac{x\sin x}{1 + x^2}dx
I \, = \, \int_0^{\infty} \sin(x)\cdot\arctan\left( \frac{1}{x} \right) dx
I \, = \, \int_{0 }^{\infty} \frac{1}{x} \cdot \sin(\tan(x)) \, dx

Have fun and gl.
 
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