Question

If f(x)=2x^4-3x^3+2x^2+x-3, explain how you know that the equation f(x)=0 has at least one real root between x=1 and x=2

Answer 1

Explanation:

by theorem :

f continu in [1 , 2]

f(1)×f(2) < 0 because : f(1) = -1 and f(2) = 15

so the equation f(x)=0 has at least one real root between x=1 and x=2

so :