Question

Which function is a quadratic function? y – 3x2 = 3(x2 + 5) + 1 y2 – 7x = 2(x2 + 6) + 7 y – 2x2 = 6(x3 + 5) – 4 y – 5x = 4(x + 5) + 9

Answer 1

Answer:

Option A.

Step-by-step explanation:

The general form of a quadratic function is  

$y=ax^2+bx+c$

It means, power of y should be 1 and highest power of x should be 2.

In option A,

$y-3x^2=3(x^2+5)+1$

$y-3x^2=3x^2+15+1$

$y=3x^2+16+3x^2$

$y=6x^2+16$

It is a quadratic function.

In option B,

$y^2-7x=2(x^2+6)+7$

Here, power of y is 2. So, it is not be a quadratic function.

In option C,

$y-2x^2=6(x^3+5)$

Here, highest power of x is 3. So, it is not be a quadratic function.

In option D,

$y-5x=4(x+5)+9$

Here, highest power of x is 1. So, it is not be a quadratic function.

Therefore, the correct option is A.