rove that x^3+4x +7 has no integral zeros
its x grade question(age 13 -14)without using calculus
Rational root theorem - Wikipedia, the free encyclopedia
The only possible rational and hence possible integral zero are
and since none of these are zero's we are done
We find that the graph is strictly increasing
. . and the only x-intercept occurs between (-2, -9) and (-1, 2)
. . (when the graph crosses the x-axis).
Hence, the only zero of the function occurs between and
Therefore, there are no integral zeros.