Solving a cubic equation using fsolve

Hi I am a beginner in matlab. I was given in problem to solve a cubic equation using fsolve. The equation is: 0.2456*x^3-2.76*x^2+7.92*x+3=0 whenever i try solving this using fsolve i get that the variable x is undefined.i dont know what im doing wrong. pls help me out.hope for a prompt reply.

Answer 1

[Walter Roberson]

You need to define your equation as a function:

eqn1 = @(x) 0.2456*x^3-2.76*x^2+7.92*x+3

Then you would fsolve(eqn1, x0) where x0 is the initial guess.

See Example 1 in the fsolve documentation