Question

Which of the following functions is quadratic?
A. f(x)=2^2
B. f(x)=3(4-x)
C. f(x)=7x(x+3)
D. f(x)= 5/x-1

Answer 1

quadratic is second power

Answer 2

c.

Answer 3

Some of these have no variable at all, or else the highest power of x is something other than 2.

Answer 4

You might be able to look right away and see what the highest power of x is, or you might want to multiply things out.

Answer 5

i thought it was either A or C... mostly C

Answer 6

7x(x+3)
7x^2+21x

Answer 7

so, c is answer.

Answer 8

A is them trying to trick you. You see that there is a ^2, which is a second power, so that's good, but it's not x^2. It's 2^2, which is simply 4. So f(x)=4 is not a quadratic, it's just a constant function.

Answer 9

@jiteshmeghwal9 Don't give answers without explanation. That's worthless.

Answer 10

k ! I m sorry.