Please Help !
Indicate if each of the following is a quadratic function or not.

a) y =( 1/x^2 + 5 ) -3
b) x^2 = y - 1
c) y = 3x - 7 + 4x^2
d) y = 6x - 3sqrtx

Question

Please Help !
Indicate if each of the following is a quadratic function or not.

a) y =( 1/x^2 + 5 ) -3
b) x^2 = y - 1
c) y = 3x - 7 + 4x^2
d) y = 6x - 3sqrtx

anonymous · Answer

$$y = \frac{ 1 }{ x^2 + 5 } -3$$

anonymous · Answer

$$y = 6x - 3\sqrt{x}$$

owlcoffee · Answer

Remember that the grade of a function is given by the variable with the highest exponent,
Say that:
$$f:f(x)= 5x+9$$
That is a polynomial function, but it is of 1st grade, why? because you see that x has an exponent of 1.
Now, a quadratic polynomial function must have a x with an exponente of two, for example:
$$g:g(x)= 9x ^{2}-3x+2$$
g is a quadratic function, because the x has a exponent of 2, meaning that, we will get two roots out of this function.

I encourage you to try finding the quadratic functions in that problem.