Answer:
b = -9
Step-by-step explanation:
The function is given as :
[tex]f(x)=3x^2+bx+4[/tex]
The axis of symmetry for this function is x = 3/2
It is required to find the value of b. The axis of symmetry of a parabola is a vertical line that intercepts its vertex at its horizontal coordinate. It can be given by :
[tex]x=\dfrac{-b}{2a}[/tex]
Putting x = 3/2 and a = 3 we get :
[tex]b=-2ax\\\\b=-2\times 3\times \dfrac{3}{2}\\\\b=-9[/tex]
So, the value of b is -9.
