Matlab - Solucion Numerica de una Ecuacion de coeficientes dados

a=input('Ingrese valor "a" : ');

b=input('Ingrese valor "b" : ');

c=input('Ingrese valor "c" : ');

a*x^2 + b*log(x)+c=150 ; %% Variable "x"

clear all

syms a b c  x real

a=10*rand, b=15*rand, c=5*rand,

ec=a*x^2 + b*log(x)+c-150 ;

x=double(solve(ec,x))

EC=inline(ec)

R=EC(x)

>> ecuacion_no_lineal

a =

   0.357116785741896

b =

  12.736939588031657

c =

   4.669966238787753

x =

  17.462717753545302

EC =

     Inline function:

     EC(x) = log(x).*1.273693958803166e1+x.^2.*3.571167857418955e-1-1.453300337612122e2

R =

     5.684341886080802e-14

>> ecuacion_no_lineal

a =

   6.787351548577735

b =

  11.366101958675001

c =

   3.715662340624581

x =

   4.368460036128416

EC =

     Inline function:

     EC(x) = log(x).*1.1366101958675e1+x.^2.*6.787351548577734-1.462843376593754e2

R =

    -2.842170943040401e-14

>> ecuacion_no_lineal

a =

   3.922270195341682

b =

   9.832168352663350

c =

   0.855933439057809

x =

   5.798205899409148

EC =

     Inline function:

     EC(x) = log(x).*9.83216835266335+x.^2.*3.922270195341682-1.491440665609422e2

R =

     0