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3 years ago

9

Amy earned $25 after babysitting for 3 hours. If she always charges the same rate, how many will she make after working for 7 ho

urs

1 answer:

Sidana [21]3 years ago

8 0

The answer is 7×3 =........

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Write t with magnitude 14 and direction 51 degrees in component form

Jlenok [28]

(14cos51, 14sin51)

8.81 i, 10.88 j

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3 years ago

Fo two disk i problem 3 what is the ratio of linear accerlation of a point on the rim of disk a

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DdffcfggtttjhsdeYWE8757Y2YU5725YW532R

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3 years ago

A jumping spider's movement is modeled by a parabola. The spider makes a single jump from the origin and reaches a maximum heigh

Stella [2.4K]

A parabola is a mirror-symmetrical U-shape.

The equation of the parabola is $\mathbf{y = -\frac{1}{640}(x - 80)^2 + 10}$
The focus is $\mathbf{Focus = (80, -1760)}$
The directrix is $\mathbf{y = \frac{1}{640}}$
The axis of the symmetry of parabola is: $\mathbf{x = 80}$

From the question, we have:

$\mathbf{Vertex: (h,k) = (80,10)}$

$\mathbf{Origin: (x,y) = (0,0)}$

The equation of a parabola is:

$\mathbf{y = a(x - h)^2 + k}$

Substitute the values of origin and vertex in $\mathbf{y = a(x - h)^2 + k}$

$\mathbf{0 = a(0 - 80)^2 + 10}$

$\mathbf{0 = a(- 80)^2 + 10}$

$\mathbf{0 = 6400a + 10}$

Collect like terms

$\mathbf{6400a =- 10}$

Solve for a

$\mathbf{a =- \frac{1}{640}}$

Substitute the values of a and the vertex in $\mathbf{y = a(x - h)^2 + k}$

$\mathbf{y = -\frac{1}{640}(x - 80)^2 + 10}$

The focus of a parabola is:

$\mathbf{Focus = (h, \frac{k+1}{4a})}$

Substitute the values of a and the vertex in $\mathbf{Focus = (h, \frac{k+1}{4a})}$

$\mathbf{Focus = (80, \frac{10+1}{4 \times -\frac{1}{640}})}$

$\mathbf{Focus = (80, -\frac{11}{\frac{1}{160}})}$

$\mathbf{Focus = (80, -11\times 160)}$

$\mathbf{Focus = (80, -1760)}$

The equation of the directrix is:

$\mathbf{y = -a}$

So, we have:

$\mathbf{y = \frac{1}{640}}$ ----- the directrix

The axis of symmetry is:

$\mathbf{x = -\frac{b}{2a}}$

We have:

$\mathbf{y = -\frac{1}{640}(x - 80)^2 + 10}$

Expand

$\mathbf{y = -\frac{1}{640}(x^2 -160x + 6400) +10}$

Expand

$\mathbf{y = -\frac{1}{640}x^2 +\frac{1}{4}x - 10 +10}$

$\mathbf{y = -\frac{1}{640}x^2 +\frac{1}{4}x }$

A quadratic function is represented as:

$\mathbf{y = ax^2 + bx + c}$

So, we have:

$\mathbf{a = -\frac{1}{640}}$

$\mathbf{b = \frac{1}{4}}$

Recall that:

$\mathbf{x = -\frac{b}{2a}}$

So, we have:

$\mathbf{x = -\frac{1/4}{2 \times -1/640}}$

$\mathbf{x = \frac{1/4}{1/320}}$

This gives

$\mathbf{x = \frac{320}{4}}$

$\mathbf{x = 80}$

Hence, the axis of the symmetry of parabola is: $\mathbf{x = 80}$

Read more about parabola at:

brainly.com/question/21685473

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3 years ago

Write an expression in simplest form for the perimeter of each figure

Juli2301 [7.4K]

QUESTION 12

The given figure has five unequal sides.

The perimeter is the distance around the figure.

So we add all the lengths of the sides of the rectangle to get,

$Perimeter = 5x + 4x + 2.8y + 2x + 2.2y$

We regroup the like terms to obtain,

$Perimeter = 5x + 4x +2x + 2.8y + 2.2y$

This will simplify to give us,

$Perimeter = 11x + 5.0y$

$Perimeter = 11x + 5y$

QUESTION 13

The given figure has two pairs of sides that are equal in length and three unequal sides.

The perimeter can be found by adding all the lengths of the sides of the of the figure.

This will give us

$Perimeter = 6b + 5a + 3b + 4 + 3a + 2b + 5a$

We regroup like terms to obtain,

$Perimeter = 6b + 2b+ + 3b + 5a + 5a +3a + 4 +$

This finally simplifies to ,

.
$Perimeter = 11b + 13a + 4 +$

QUESTION 14

This plane figure has four sides that are equal to 4j and two sides that are equal to 2h.

We add all the lengths of the sides of the plane figure to get,

$Perimeter =4j + 4j+ 4j+ 4j + 2h + 2h$

This will simplify to give us,

$Perimeter =16j + 4h$

6 0

3 years ago

Help me find “a” and “b” please!!

sattari [20]

Answer:

36-A

9-B

Step-by-step explanation:

7 0

3 years ago