Question and Answers Forum

All Questions      Topic List

Integration Questions

Previous in All Question      Next in All Question      

Previous in Integration      Next in Integration      

Question Number 125187 by bemath last updated on 08/Dec/20

  ∫ (dx/( (√(sin^3 x)) (√(cos^5 x)))) ?

$$\:\:\int\:\frac{{dx}}{\:\sqrt{\mathrm{sin}\:^{\mathrm{3}} {x}}\:\sqrt{\mathrm{cos}\:^{\mathrm{5}} {x}}}\:? \\ $$

Answered by liberty last updated on 08/Dec/20

I=∫ (√((((1/(cos^3 x))))/(tan^3 x cos^5 x))) dx = ∫(dx/( (√(tan^3 x)) (√(cos^8 x))))  I = ∫ ((sec^4 x)/( (√(tan^3 x)))) dx = ∫ (((1+tan^2 x) sec^2 x)/( (√(tan^3 x)))) dx  letting tan x = p ⇒ sec^2 x dx = dp  I=∫(((1+p^2 ))/p^(3/2) ) dp = ∫ (p^(−(3/2))  + p^(1/2) ) dp  I= −2p^(−(1/2))  + (2/3)p^(3/2)  + c   I = −(2/( (√(tan x)))) + ((2(√(tan^3 x)))/3) + c

$${I}=\int\:\sqrt{\frac{\left(\frac{\mathrm{1}}{\mathrm{cos}\:^{\mathrm{3}} {x}}\right)}{\mathrm{tan}\:^{\mathrm{3}} {x}\:\mathrm{cos}\:^{\mathrm{5}} {x}}}\:{dx}\:=\:\int\frac{{dx}}{\:\sqrt{\mathrm{tan}\:^{\mathrm{3}} {x}}\:\sqrt{\mathrm{cos}\:^{\mathrm{8}} {x}}} \\ $$$${I}\:=\:\int\:\frac{\mathrm{sec}\:^{\mathrm{4}} {x}}{\:\sqrt{\mathrm{tan}\:^{\mathrm{3}} {x}}}\:{dx}\:=\:\int\:\frac{\left(\mathrm{1}+\mathrm{tan}\:^{\mathrm{2}} {x}\right)\:\mathrm{sec}\:^{\mathrm{2}} {x}}{\:\sqrt{\mathrm{tan}\:^{\mathrm{3}} {x}}}\:{dx} \\ $$$${letting}\:\mathrm{tan}\:{x}\:=\:{p}\:\Rightarrow\:\mathrm{sec}\:^{\mathrm{2}} {x}\:{dx}\:=\:{dp} \\ $$$${I}=\int\frac{\left(\mathrm{1}+{p}^{\mathrm{2}} \right)}{{p}^{\frac{\mathrm{3}}{\mathrm{2}}} }\:{dp}\:=\:\int\:\left({p}^{−\frac{\mathrm{3}}{\mathrm{2}}} \:+\:{p}^{\frac{\mathrm{1}}{\mathrm{2}}} \right)\:{dp} \\ $$$${I}=\:−\mathrm{2}{p}^{−\frac{\mathrm{1}}{\mathrm{2}}} \:+\:\frac{\mathrm{2}}{\mathrm{3}}{p}^{\frac{\mathrm{3}}{\mathrm{2}}} \:+\:{c}\: \\ $$$${I}\:=\:−\frac{\mathrm{2}}{\:\sqrt{\mathrm{tan}\:{x}}}\:+\:\frac{\mathrm{2}\sqrt{\mathrm{tan}\:^{\mathrm{3}} {x}}}{\mathrm{3}}\:+\:{c}\: \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com