Answer:
[tex]\boxed{\boxed{B.\ f(x)=\dfrac{3}{4}x^2+2x-5}}[/tex]
Step-by-step explanation:
Quadratic function-
It is a function that can be represented by an equation of the form [tex]f = ax^2 + bx + c[/tex], where [tex]a\neq 0[/tex]
In a quadratic function, the greatest power of the variable is 2.
As in the first option the highest power is 3, so it is not a quadratic function.
Even though the power of x is 2 in the third option, but as it is in the denominator, so the overall power of x becomes -2. Hence it is not a quadratic function.
As the coefficient of [tex]x^2[/tex] is 0 in case of fourth option, so it is not a quadratic function.
Equation in option 2 satisfies all the conditions of quadratic function, hence it is the quadratic function.
