Question

The axis of symmetry for the graph of the function f(x)=3x2+bx+4 is x equals three-halves. What is the value of b?

Answer 1

Answer:

The value of b = - 9.

Step-by-step explanation:

Given :

$\implies \bf f(x)=3x^{2} +bx+4$

$\implies \bf x = \dfrac{3}{2}$

To Find :

The value of B.

Solution :

We know that :

The axis of symmetry of a parabola is a vertical line that intercepts its vertex at its horizontal coordinate.

So,

$\bigstar\;\boxed{\bf{x = -\dfrac{b}{2a}}}\qquad[\bf Where\;a = 3]$

Putting the values,

$\implies \sf x=-\dfrac{b}{2a}}\\ \\ \\\implies\sf \dfrac{3}{2} =-\dfrac{b}{2(3)}\\ \\ \\\implies \sf \dfrac{3}{2}=-\dfrac{b}{6}\\\\ \\\implies \sf b=-\dfrac{6(3)}{2}\\ \\ \\\implies \bf b=-9$

$\therefore$ The Value of B = - 9.

Answer 2

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