In the equation z=x^2-3y, find the value of z when x=-3 and y=4

Click here please. The problems are in picture format

padilas [110]

First picture:

You got the first two right (good job!), so I'll just tackle the third one. If you have to compute $f(x-4)$ , it means that you have to substitute $x-4$ in place of $x$ . Differently from the first two points, this will generate a new function, rather than a specific value:

$f(x) = \sqrt{x+4}+2 \implies f(x-4) = \sqrt{(x-4)+4}+2 = \sqrt{x}+2$

Second picture:

Given the point $(x,y)$ highlighted in the picture, you can deduce that the base is $2x$ units long (since it spans from $(-x,0)$ to $(x,0)$ ) and the height is $y$ units long (because it spans from $(x,0)$ to $(x,y)$ ). So, the area of the rectangle is the multiplication between base and height:

$A = 2xy$

But we know that $y=f(x)=\sqrt{36-x^2}$ , so we have

$A = 2x\sqrt{36-x^2}$

The domain of this function is given by the domain of the square root: we want its argument to be non, negative, so we have

$36-x^2 \geq 0 \iff x^2 \leq 36 \iff -6 \leq x \leq 6$

But since the problem is symmetric, the answer is

$0 \leq x \leq 6$

You can only see the answer $0 < x < 6$ because, if you choose $x=0$ or $x=6$ , the rectangle degenerates to a segment, and your exercise doesn't like this scenario, apparently

4 0

3 years ago

Using Euler's relation, derive the following relationships:a. Cosθ=½(e^jθ+e^−jθ)b. Sinθ=½(e^jθ−e(^−jθ)

Montano1993 [528]

Answer:

a. cosθ = ¹/₂[e^jθ + e^(-jθ)] b. sinθ = ¹/₂[e^jθ - e^(-jθ)]

Step-by-step explanation:

a.We know that

e^jθ = cosθ + jsinθ and

e^(-jθ) = cosθ - jsinθ

Adding both equations, we have

e^jθ = cosθ + jsinθ

+

e^(-jθ) = cosθ - jsinθ

e^jθ + e^(-jθ) = cosθ + cosθ + jsinθ - jsinθ

Simplifying, we have

e^jθ + e^(-jθ) = 2cosθ

dividing through by 2 we have

cosθ = ¹/₂[e^jθ + e^(-jθ)]

b. We know that

e^jθ = cosθ + jsinθ and

e^(-jθ) = cosθ - jsinθ

Subtracting both equations, we have

e^jθ = cosθ + jsinθ

-

e^(-jθ) = cosθ - jsinθ

e^jθ + e^(-jθ) = cosθ - cosθ + jsinθ - (-jsinθ)

Simplifying, we have

e^jθ - e^(-jθ) = 2jsinθ

dividing through by 2 we have

sinθ = ¹/₂[e^jθ - e^(-jθ)]

4 0

3 years ago

PLEASE HELP ASAP !!

wariber [46]

Answer:

First figure: $954cm^3$

Second figure: $1,508yd^3$

Third figure:

Height= q
Side length = r

Fourth figure:  $726cm^3$

Explanation:

A. First figure:

1. Formula:

$\text{Volume of a cylinder}=\pi \times radius^2\times length$

2. Data:

radius = 9cm / 2 = 4.5cm

length = 15 cm

3. Substitute in the formula and compute:

$Volume=\pi \times (4.5cm)^2\times (15cm)\approx 954cm^3\approx 954cm^3$

B. Second figure

1. Formula:

$\text{Volume of a leaned cylinder}=\pi \times radius^2\times height$

2. Data:

radius = 12yd

height = 40 yd

3. Substitute and compute:

$Volume=\pi \times (12yd)^2\times (40yd)\approx 1,507.96yd^3\approx 1,508yd^3$

C) Third figure

a) The height is the segment that goes vertically upward from the center of the base to the apex of the pyramid, i.e. q .

The apex is the point where the three leaned edges intersect each other.

b) The side length is the measure of the edge of the base, i.e. r .

When the base of the pyramid is a square the four edges of the base have the same side length.

D) Fourth figure

1. Formula

The volume of a square pyramide is one third the product of the area of the base (B) and the height H).

$Volume=(1/3)B\times H$

2. Data:

height: H = 18cm

side length of the base: 11 cm

3. Calculations

a) Calculate the area of the base.

The base is a square of side length equal to 11 cm:

$\text{Area of the base}=B=(11cm)^2=121cm^2$

b) Volume of the pyramid:

$Volume=(1/3)B\times H=(1/3)\times 121cm^2\times 18cm=726cm^3$

4 0

3 years ago

Read 2 more answers

Consider the function shown.

Vanyuwa [196]

Answer:

Decreasing from x = 1 to x = 6.

Step-by-step explanation:

4 0

3 years ago

What is the height of a trapezoid with an area of 99 in.2 whose bases are 6 in. and 12 in.?

vladimir1956 [14]

Answer:

trapezoid area = ((sum of the bases) ÷ 2) • height

trapezoid area = ((6 + 12) / 2) * height

trapezoid area = 18 / 2 * height

height = 99/9 = 11

Step-by-step explanation:

7 0

3 years ago