Need help asap with math question! Offering double points!

Question

asked Dec 5, 2019 21.9k views

1 Answer

Prasad Rajapaksha · Answer 1 · 2019-12-12T13:34:58+0000

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.