Identify which equation is a quadratic equation.

Question

anonymous · Answer

Identify which equation is a quadratic equation.

 y = 3x + 4

 y + x2 = (x − 2)(x + 7)

 y = −4x(x − 4) + 2x

 y + 3 = (x + 12)(x2 + 2)

shubhamsrg · Answer

"degree", ever heard that word ?

shubhamsrg · Answer

in terms of polynomials.
"polynomials", ever heard that word ?

anonymous · Answer

yes

shubhamsrg · Answer

what do you understand by degree of a polynomial ?

anonymous · Answer

the highest degree of all the terms

shubhamsrg · Answer

yes.
now, a polynomial with degree=2 is called a quadratic function.
does this help you?

anonymous · Answer

yes thank you very much!

shubhamsrg · Answer

well, glad to help ^_^

anonymous · Answer

so does this mean the answer would be  y + 3 = (x + 12)(x2 + 2) @shubhamsrg

shubhamsrg · Answer

after simplification, you will see degree of this is 3
so this is not the answer.
try again.

anonymous · Answer

y + x^2 = (x − 2)(x + 7)? @shubhamsrg

shubhamsrg · Answer

you are confirming all options one by one! -_-

anonymous · Answer

no those are the ones i thought it was.. @shubhamsrg

shubhamsrg · Answer

hmm, do you simplify ?
after simplification, you'll get to know if degree of x is 2 or not.

anonymous · Answer

y + x^2 = (x − 2)(x + 7) this is the right answer?

shubhamsrg · Answer

no!!

anonymous · Answer

then what would it be because i checked myself?