Articles
Register
Sign In
Search
Texoce
@Texoce
April 2019
1
124
Report
Coucou j'ai besoin d'aide pour l'exercice 99 svp je comprend pas
Please enter comments
Please enter your name.
Please enter the correct email address.
Agree to
terms and service
You must agree before submitting.
Send
Lista de comentários
isapaul
Verified answer
Bonjour
ABCD et un carré de 5 cm de côté
BM = DN = x
1)
on a
Aire ABCD = 5² = 25 cm²
Aire CNPM = (5-x)²
Aire ABM = (AB * MB)/2 = (5x)/2
Aire AND = (AD * DN)/2 ) = (5x)/2
2)
Aire Flèche = Aire ABCD - Aire MCNP - Aire ABM - Aire AND
Aire Flèche = 25 - (5 - x)² - (5x)/2 - (5x)/2
Aire Flèche = 25 - 25 - x² + 10x - 5x
Aire Flèche = -x² + 5x
3)
A(x) = - (x-5/2)²+25/4
A(x) = - (x² - 10x/2 +25/4) +25/4
A(x) = -x² + 10x/2
A(x) = -x² +5x ce qu'il fallait démontrer...
4)
la dérivée sera A ' (x) = - 2x + 5 donc A' (x) = 0 pour x = 5/2 = 2.5
Sens de Variation et tableau
x 0 ___________________ 2.5 __________________________ 5
A ' (x) -5 positive 0 négative -5
A(x) 0 croissante 6.25 décroissante 0
figure 1 : A(1.4) = 5.04
figure 2 : A(2.9) = 6.09
figure 3: A(4.3) = 3.01
5)
A(x) = 5.25 soit
-x²+5x = 5.25
-x² + 5x - 5.25 = 0
delta = 25 - 21 = 4 donc racine delta ou Vdelta = 2
deux solutions
x ' = (-5 - 2)/-2 = 7/2 = 3.5
x " = ( -5 +2) /-2 = 3/2 = 1.5
2 votes
Thanks 1
isapaul
De rien
More Questions From This User
See All
texoce
June 2021 | 0 Respostas
Responda
texoce
June 2021 | 0 Respostas
Responda
texoce
June 2021 | 0 Respostas
Responda
texoce
June 2021 | 0 Respostas
Responda
texoce
June 2021 | 0 Respostas
Responda
texoce
June 2021 | 0 Respostas
Coucou j'ai besoin d'aide pour lexercices 15
Responda
Texoce
April 2019 | 0 Respostas
Responda
×
Report "Coucou j'ai besoin d'aide pour l'exercice 99 svp je comprend pas.... Pergunta de ideia de Texoce"
Your name
Email
Reason
-Select Reason-
Pornographic
Defamatory
Illegal/Unlawful
Spam
Other Terms Of Service Violation
File a copyright complaint
Description
Helpful Links
Sobre nós
Política de Privacidade
Termos e Condições
direito autoral
Contate-Nos
Helpful Social
Get monthly updates
Submit
Copyright © 2024 ELIBRARY.TIPS - All rights reserved.
Lista de comentários
Verified answer
BonjourABCD et un carré de 5 cm de côté
BM = DN = x
1)
on a
Aire ABCD = 5² = 25 cm²
Aire CNPM = (5-x)²
Aire ABM = (AB * MB)/2 = (5x)/2
Aire AND = (AD * DN)/2 ) = (5x)/2
2)
Aire Flèche = Aire ABCD - Aire MCNP - Aire ABM - Aire AND
Aire Flèche = 25 - (5 - x)² - (5x)/2 - (5x)/2
Aire Flèche = 25 - 25 - x² + 10x - 5x
Aire Flèche = -x² + 5x
3)
A(x) = - (x-5/2)²+25/4
A(x) = - (x² - 10x/2 +25/4) +25/4
A(x) = -x² + 10x/2
A(x) = -x² +5x ce qu'il fallait démontrer...
4)
la dérivée sera A ' (x) = - 2x + 5 donc A' (x) = 0 pour x = 5/2 = 2.5
Sens de Variation et tableau
x 0 ___________________ 2.5 __________________________ 5
A ' (x) -5 positive 0 négative -5
A(x) 0 croissante 6.25 décroissante 0
figure 1 : A(1.4) = 5.04
figure 2 : A(2.9) = 6.09
figure 3: A(4.3) = 3.01
5)
A(x) = 5.25 soit
-x²+5x = 5.25
-x² + 5x - 5.25 = 0
delta = 25 - 21 = 4 donc racine delta ou Vdelta = 2
deux solutions
x ' = (-5 - 2)/-2 = 7/2 = 3.5
x " = ( -5 +2) /-2 = 3/2 = 1.5