Respuesta :
Answer:
b = -9.
Step-by-step explanation:
f(x)=3x2+bx+4 Convert to vertex form:
= 3(x^2 + (b/3)x) + 4
= 3 [ ( x + b/6)^2 - (b/6)^2] + 4
So the axis of symmetry is x = -b/6 = 3/2
so -2b = 18
b = -9.
Answer:
The value of b is -9.
Step-by-step explanation:
The given function is
[tex]f(x)=3x^{2} +bx+4[/tex]
We know by given, the axis of symmetry is [tex]x=\frac{3}{2}[/tex]
According to the theory, the axis of symmetry of a parabola is a vertical line that intercepts its vertex at its horizontal coordinate, which can be found we this formula
[tex]x=-\frac{b}{2a}[/tex] Where [tex]a=3[/tex]
Know we just need to replace all given values and solve for [tex]b[/tex]
[tex]x=-\frac{b}{2a}}\\\frac{3}{2} =-\frac{b}{2(3)}\\\frac{3}{2}=-\frac{b}{6}\\ b=-\frac{6(3)}{2} \\b=-9[/tex]
Therefore, the value of b is -9.
