No.

Nonlinear functions

Zero

1

$f_1\left(x\right)=x\cos x-x^3+x-2$

−1.531439613

2

$f_2\left(x\right)=x^3-{\text{e}}^x+2x-1$

1.261556999

3

$f_3\left(x\right)=5\sin \left(x+2\right)+{\text{e}}^x+x-1$

−1.521345295

4

$f_4\left(x\right)=\left(x^2-5x+7\right){\text{e}}^x+x-3$

−1.248014042

5

$f_5\left(x\right)=5{\cos }^3\left(x-2\right)-4{\text{e}}^x-3x^3+1$

−1.199683477