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 57235 by maxmathsup by imad last updated on 31/Mar/19

calculate ∫_0 ^(π/2)  ((cosx −sinx)/(√(cos^8 x +sin^8 x))) dx

calculate0π2cosxsinxcos8x+sin8xdx

Commented by maxmathsup by imad last updated on 01/Apr/19

changement x=(π/2)−t give I =−∫_0 ^(π/2)  ((cos((π/2)−t)−sin((π/2)−t))/(√(cos^8 ((π/2)−t)+sin^8 ((π/2)(t))))(−dt)  =∫_0 ^(π/2)    ((sint −cost)/(√(sin^8 t +cos^8 t))) dt =−I ⇒2I =0 ⇒I =0 .

changementx=π2tgiveI=0π2cos(π2t)sin(π2t)cos8(π2t)+sin8(π2(t)(dt)=0π2sintcostsin8t+cos8tdt=I2I=0I=0.

Answered by tanmay.chaudhury50@gmail.com last updated on 01/Apr/19

I=∫_0 ^(π/2) ((cosx−sinx)/(√(cos^8 x+sin^8 x)))dx  =∫_0 ^(π/2) ((sinx−cosx)/(√(sin^8 x+cos^8 x)))dx [∫_0 ^a f(x)dx=∫_0 ^a f(a−x)dx]  2I=0→I=0

I=0π2cosxsinxcos8x+sin8xdx=0π2sinxcosxsin8x+cos8xdx[0af(x)dx=0af(ax)dx]2I=0I=0

Terms of Service

Privacy Policy

Contact: info@tinkutara.com