1. [tex]a x^{2} +2x=b x^{3} [/tex] pour x=1
a*[tex] 1^{2} + 2*1=b* 1^{3} [/tex]
a+2=b
2. f"(x)= [tex] \left \{ {{y=2ax+2} \atop {x=3b x^{2} }} \right. [/tex]
[tex]2ax+2=3b x^{2} [/tex], x=1
2a*1+2=3b*1^2
2a+2=3b
3.[tex] \left \{ {{y=a+2=b} \atop {x=2a+2=3b}} \right. [/tex]
2a+2=3(a+2)
2a-3a=6-2
-a=4/ *(-1)
a=-4, b=-4+2=-2
f(x)= 2x^3-4x^2+2x
f(2)= 2*2^3 - 4*2^2 + 2*2=4
