Forum de Mathématiques: Maths-Forum

I can read in French and understand the most part of it, but it's difficult to me to write in French.
Anyway, in the next posts I'll try to write in French, but you must excuse my mistakes.

Let be the width, the length of rectangle and his area.
To find x and y we have to solve the system

b) f(x)= 4xpuissance 3-2x²+3x-1 f'(x)=12x²-4x+3 je n'ai pas de racines donc je pense (j'en suis vraiment pas sure que ça s'arrete là !!!) c) f(x) = (-2x+3)/(5x-2) f'(x)= -19/(5x-2)² de -00 à 2/5 j'ai + de 2/5 à +00 j'ai - b) f'(x)=12x^2-4x+3>0, \ \forall x\in\mathbf{R} c) f'(x&#...

Sorry, I can't write in French. Let y=ax+b be the equation of the given line d_1 and d the distance between the two lines. The line d_2 must have the same slope as d_1 (they are parallel). So d_2: \ y=ax+c . Let M(x_0,y_0) be a point on d_1 . You can find such a point by giving to x a value ...

Let AC\cap BD=O We have AC=BD, \ AI=DI, \ BI=CI\Rightarrow \triangle AIC\equiv\triangle DIB . In the quadrilater AOID we have \widehat{OAI}=\widehat{ODI}\Rightarrow the quadrilater is cyclic. Then \widehat{AID}=\widehat{AOD}=90 . So the triangle AID is right isosceles and I is the center of the squa...

II°/ Soit la fonction f définie sur Df = ]-infini; 1[ u ]1, + infini[ par : f(x) = x+1 / x-1 et Cf sa courbe representative. 1° Determiner les reels a et b tels que pour tout x de Df f(x) = a + b/x-1 2° Determiner les limites du voisinage de l'infini, de 1+, de 1-. En deduire les eventuelles asynpt...