Question and Answers Forum

All Questions      Topic List

None Questions

Previous in All Question      Next in All Question      

Previous in None      Next in None      

Question Number 202295 by liuxinnan last updated on 24/Dec/23

psinθcon^2 θ=a  pcosθsin^2 θ=b  p≠0    θ∈(0 ,(π/2))  prove p=(((a^2 +b^2 )^(3/2) )/(ab))

psinθcon2θ=apcosθsin2θ=bp0θ(0,π2)provep=(a2+b2)32ab

Answered by 1990mbodji last updated on 24/Dec/23

     Exercice :     p sinθ cos^2 θ = a    et    p cosθ sin^2  θ = b ou^�  θ∈]0;(π/2)[.    Montrons que  p = (((a^2 +b^2 )^(3/2) )/(ab)) .     ab = p^2 sin^3 θ cos^3 θ   et  a^2 +b^2  = p^2 sin^2 θ cos^2 θ (cos^2 θ+sin^2 θ)    ⇒ abp = (p sinθ cosθ)^3   et  a^2 +b^2  = (p sinθ cosθ)^2      ⇒ p sinθ cosθ = (abp)^(1/3)    et   p sinθ cosθ = (a^2 +b^2 )^(1/2)      ⇒ abp = (a^2 +b^2 )^(3/2)   ⇒ p = (((a^2 +b^2 )^(3/2) )/(ab)) .

Exercice:psinθcos2θ=aetpcosθsin2θ=bou`θ]0;π2[.Montronsquep=(a2+b2)32ab.ab=p2sin3θcos3θeta2+b2=p2sin2θcos2θ(cos2θ+sin2θ)abp=(psinθcosθ)3eta2+b2=(psinθcosθ)2psinθcosθ=(abp)13etpsinθcosθ=(a2+b2)12abp=(a2+b2)32p=(a2+b2)32ab.

Commented by MathematicalUser2357 last updated on 26/Dec/23

no french

nofrench

Terms of Service

Privacy Policy

Contact: info@tinkutara.com