Find the x intercepts of the parabola with vertex (-1,-16) and y intercept (0,-15)

1 answer:

8 0

first, write the equation of the parabola in the required form: 
(y - k) = a·(x - h)² 

Here, (h, k) is given as (-1, -16). 
So you have: 
(y + 16) = a · (x + 1)² 

Unfortunately, a is not given. However, you do know one additional point on the parabola: (0, -15): 

-15 + 16 = a· (0 + 1)² 
.·. a = 1 

.·. the equation of the parabola in vertex form is 
y + 16 = (x + 1)² 

The x-intercepts are the values of x that make y = 0. So, let y = 0: 

0 + 16 = (x + 1)² 
16 = (x + 1)² 

We are trying to solve for x, so take the square root of both sides - but be CAREFUL! 

± 4 = x + 1 ...... remember both the positive and negative roots of 16...... 

Solving for x: 
x = -1 + 4, x = -1 - 4 
x = 3, x = -5. 

Or, if you prefer, (3, 0), (-5, 0).

You might be interested in

A and B are two similar ornaments in the shape of a fish. The surface area of 44.8 cm and the surface area of B 179.2 cm Find th

ASHA 777 [7]

Answer:

400 cm

Step-by-step explanation:

1 cm = 1000m

44.8 cm=?

8 0

2 years ago

The area of a rectangle is 256.5 m.cuadrados If the length is 18m what is the perimeter of the rectangle

Alex_Xolod [135]

The perimeter for the rectangle is 64.5m.

3 0

3 years ago

H(x) = x3 + 7 Determine whether the function is one-to-one.

zubka84 [21]

Answer:

we conclude that the function is one-to-one.

Step-by-step explanation:

A function will a one-to-one function if it

passes the vertical line test to make sure it is indeed a function, and

also a horizontal line test to make sure it is it one-to-one.

In other words,

The function will be one-to-one if it passes the vertical line test, and also if the horizontal line only cuts the graph of the function in one place.

The reason is that there must be only one x-value for each y-value.

Given the function

$h\left(x\right)\:=\:x^3\:+\:7$

Have a look at the attached graph.

The red portion represents the graph of the function $h\left(x\right)\:=\:x^3\:+\:7$ .

The green portion represents the graph of x=2 which is basically a vertical line test. Vertical line indicates that it cuts the cuts the graph of the function in one place. So it is clear that $h\left(x\right)\:=\:x^3\:+\:7$ is indeed a function.

The blue line represents the graph of y=9, which is basically a horizontal line test. Horizontal line indicates that it cuts the cuts the graph of the function in one place. So it is clear that $h\left(x\right)\:=\:x^3\:+\:7$ is a one-to-one function, as there is only one x-value for each y-value.

Therefore, we conclude that the function is one-to-one.