Respuesta :

Answer:

3rd one

4th one

5th one

8th one

Step-by-step explanation:

solve for the y intercept by plugging in f(0)

0²-4(0)-21= -21

Therefore (0,-21) is a y intercept

Factor to find the x intercepts

(x+3)(x-7)

Therefore the intercepts are

(-3,0) (7,0)

THis function has a positive coeficcent and an even degree

therefore as x approaches infinity it's infinity

and as x approaches negative infinity it's infinity