Answer:
The bird will take 0.88 seconds to reach a height of 40 feet in the air for the first time
Step-by-step explanation:
we have
This is a vertical parabola open downward
The vertex represent a maximum
where
h is the height of the bird
t is the amount of time, in seconds, the bird had been in the air
For h=40 ft
substitute in the quadratic equation
The formula to solve a quadratic equation of the form
is equal to
in this problem we have
so
substitute in the formula
therefore
The bird will take 0.88 seconds to reach a height of 40 feet in the air for the first time
Divide by 2 and find out.
4/9 / 2
Multiply by its reciprocal:
4/9 * 1/2
Multiply the numerators and denominators together:
4/18
4/18 does not equal 8/18, so 4/9 isn't half of 8/18.
Just follow this operation.
Find the two perfectly squared factors the multiple to your number.
Take the square root of those perfect factors then multiple them.
The vertex is exactly half way between directrix and focus. In this case the vertex is (8,-7)
(h,k)
P is the distance between the vertex and either the directrix or focus, in this case p = 1.
a = 1/(4p) or 1/(4*1) or 1/4
write the equation in vertex form
y = a(x-h)^2 + k
y = 1/4(x-8)^2 -7
is a quadratic function, so its graph is a parabola.
Notice that the coefficient of x is 0, this always means that the axis of symmetry is the y-axis.
That is, the vertex of the parabola is in the y-axis, so the x-coordinate of the vertex is 0.
for x=0, y=-1. So the vertex is (0, -1)
The coefficient of
is negative. This means that the parabola opens downwards, so the vertex is a maximum.
Answer: (0, -1) , maximum (none of the choices)
