ANSWER
The minimum value is -0.8
EXPLANATION
The given
[tex]f(x)=x^2+4.2x+3.6[/tex]
The minimum value is the y-value of the vertex (minimum point).
To find the minimum value of the function, we substitute x=-2 into the function to get;
[tex]f( - 2)=( - 2)^2+4.2( - 2)+3.6[/tex]
[tex]f( - 2)=4 - 8.4+3.6 = - 0.8[/tex]
The minimum value is -0.8