Question

Im having trouble with this intermediate value problem and i cant seem to find clear cut steps to follow. here it is X^3-4x+1=0; [1,2]

Answer 1

plug in x=1; get the value

plug in x=2; get the value

if the have different signs; they had to have crossed at some point

Answer 2

if they have the same signage; then it cannot be determined of they crossed or not

Answer 3

also, check that the function is continuous. since yours is regular polynomial, it is continous. so no worries there