Question

Need help asap with math question! Offering double points!

Answer 1

Q6. Given

`y= ax^2 + bx + c`

the vertex is in between the two zeros; it's

`x=- (b)/(2a)`

which we know from the quadratic formula is the midpoint between the zeros.

We get a negative x coordinate when a and b have the same signs. Let's go through the choices.

`y = -3x^2 -7x + 4` -3 and -7 have the same sign, negative x, CHECK

`y = -3x^3 + 7x - 4` different signs, nope

`y = 3x^2 -7x + 4` different signs, nope

`y = 3x^2 + 7x - 4` same sign, CHECK

1st and 4th choice.

Q7.

The correct first step of evaluating the polynomial at x=3/4 is to substitute 3/4 for x, first choice.