please answer this question​

Answer:  Choice D

15(cos85° + i sin85°)

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Explanation:

Let's say we had these two general complex numbers, which are in polar form.

[tex]z_1 = r_1*\left(\cos(\theta_1)+i*\sin(\theta_1)\right)\\\\z_2 = r_2*\left(\cos(\theta_2)+i*\sin(\theta_2)\right)\\\\[/tex]

We can abbreviate them into the shorthand form

[tex]z_1 = r_1*\text{cis}(\theta_1)\\\\z_2 = r_2*\text{cis}(\theta_2)\\\\[/tex]

The notation "cis" stands for "cosine i sine".

Now that we have those complex numbers set up, multiplying them is as simple as saying this:

[tex]z_1*z_2 = (r_1*r_2)*\text{cis}(\theta_1+\theta_2)[/tex]

We do two basic things:

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With all that in mind, let's tackle the problem your teacher gave you.

The given complex numbers

[tex]z_1 = 5*\left(\cos(15^{\circ})+i*\sin(15^{\circ})\right)\\\\z_2 = 3*\left(\cos(70^{\circ})+i*\sin(70^{\circ})\right)\\\\[/tex]

abbreviate into

[tex]z_1 = 5*\text{cis}(15^{\circ})\\\\z_2 = 3*\text{cis}(70^{\circ})\\\\[/tex]

then those multiply to

[tex]z_1*z_2 = (r_1*r_2)*\text{cis}(\theta_1+\theta_2)\\\\z_1*z_2 = (5*3)*\text{cis}(15+70)\\\\z_1*z_2 = 15\text{cis}(85^{\circ})\\\\z_1*z_2 = 15\left(\cos(85^{\circ})+i\sin(85^{\circ})\right)\\\\[/tex]

which is why choice D is the final answer.

Answer:

The expression for the height of the solid is:

[tex]\displaystyle h = x^2+x-9[/tex]

Step-by-step explanation:

Recall that the volume of a rectangular solid is given by:

[tex]\displaystyle V = \ell wh[/tex]

Where l is the length, w is the width, and h is the height.

We know that the volume is given by the polynomial:

[tex]\displaystyle V = 3x^4-3x^3-33x^2+54x[/tex]

And that the length and width are given by, respectively:

[tex]\displaystyle \ell = 3x \text{ and } w =x-2[/tex]

Substitute:

[tex]\displaystyle 3x^4-3x^3-33x^2+54x=(3x)(x-2)h[/tex]

We can solve for h. First, divide both sides by 3x:

[tex]\displaystyle \frac{3x^4-3x^3-33x^2+54x}{3x}=(x-2)h[/tex]

Divide each term:

[tex]\displaystyle x^3-x^2-11x+18=(x-2)h[/tex]

To solve for h, divide both sides by (x - 2):

[tex]\displaystyle h = \frac{x^3-x^2-11x+18}{x-2}[/tex]

Since this is a polynomial divided by a binomial in the form of (x - a), we can use synthetic division, where a = 2. This is shown below. Therefore, the expression for the height of the solid is:

[tex]\displaystyle h = x^2+x-9[/tex]

Answer:

6

Step-by-step explanation:

again ?

7 = (3x - 4)/2

14 = 3x - 4

18 = 3x

x = 6

Answer:

each costumer owe $35.40

Step-by-step explanation:

so, u get 247.79÷7 (cuz it is 7 people)

u get 35.40.

to check just get 35.40×7 and u will revice their total.

hopefully this answer can help you to answer the next question.

Answer:

The area is 72 cm².

Step-by-step explanation:

Since it is equivalent triangle

h = b

so,

b + b + b (since all sides are equal)= 36 cm

3b = 36 cm

or, b = 36/3

so, b = 12 cm

so

area of triangle = (1/2)×b×h

= (1/2)×12cm×12cm

= 6cm × 12cm

= 72 cm²

7^2 + 6^2 = h^2

49 + 36 = h^2

85 = h^2

√85 = h

h = 9.21m

Answered by Gauthmath must click thanks and mark brainliest

Answer:

I am not sure but it may be option c .

Step-by-step explanation:

I chose option c because in parallelogram the opposite sides are parallel .

Answer: The range is  [tex]\{y \in \mathbb{R}\ | \ y \le -6\}[/tex]

Explanation:

The parabola opens down, forming a "frowny face" in a way (just without the eyes). Or you can think of it as a hill or mountain. This means that the vertex (-3,-6) is at the top of that mountain. It's the highest point of that parabola.

The range is the set of all possible y values. We see that y = -6 is the largest it can get. So y = -6 or y is smaller than this. We would then write [tex]y \le -6[/tex] to describe all the possible y values.

Therefore, the range is [tex]\{y \in \mathbb{R}\ | \ y \le -6\}[/tex]

This translates to "y is a real number such that y is -6 or smaller".

So the second answer you wrote is close, but you forgot the "or equal to" portion of the inequality sign.

See below for a visual example of what's going on.

Answer:

R = [tex]\left[\begin{array}{ccc}-3&-2\\1&-3\\\end{array}\right][/tex]

Step-by-step explanation:

P - Q + R = I ( I is the identity matrix )

[tex]\left[\begin{array}{ccc}2&4\\3&5\\\end{array}\right][/tex] - [tex]\left[\begin{array}{ccc}-2&2\\4&1\\\end{array}\right][/tex] + R = [tex]\left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right][/tex] ( subtract corresponding elements )

[tex]\left[\begin{array}{ccc}2-(-2)&4-2\\3-4&5-1\\\end{array}\right][/tex] + R = [tex]\left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right][/tex]

[tex]\left[\begin{array}{ccc}4&2\\-1&4\\\end{array}\right][/tex] + R = [tex]\left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right][/tex]

R = [tex]\left[\begin{array}{ccc}1&0\\0&1\\\end{array}\right][/tex] - [tex]\left[\begin{array}{ccc}4&2\\-1&4\\\end{array}\right][/tex] = [tex]\left[\begin{array}{ccc}-3&-2\\1&-3\\\end{array}\right][/tex]

Answer:

i think the answet is 0.625

Answer:

The answer is 12.

Step-by-step explanation:

Since one of the sides on the smaller polygon is two and on the other one is six that must mean the scale is multiply by 3 because 2x3=6. So 4 times 3 is 12.

So, w = 12

Answer:

I think C sorry if wrong

Step-by-step explanation:

Answer:

If its supposed to be simplify it will be -7 . If your finding the derivative it is 0.

Step-by-step explanation:

Answer:

x = 98

Step-by-step explanation:

x and 82 are adjacent angles on a straight line and sum to 180° , then

x + 82 = 180 ( subtract 82 from both sides )

x = 98

Answer:

B) ΔABC and ΔA′B′C′ are congruent.

Step-by-step explanation:

Given

See attachment for [tex]\triangle ABC[/tex] and [tex]\triangle A'B'C'[/tex]

Required

Determine the relationship between both triangles

The single line on all sides of both triangles implies that the sides of the triangles are equal

i.e.

[tex]\triangle ABC \cong \triangle A'B'C'[/tex] --- sides

Similarly, the same mark on the three angles of both triangles means that the angles of the both triangles are equal

i.e.

[tex]\triangle ABC \cong \triangle A'B'C'[/tex] --- angles

Hence, both triangles are congruent

Answer:

B) ΔABC and ΔA′B′C′ are congruent.

Step-by-step explanation:

Answer:

15

Step-by-step explanation:

first find f which is (8-3) × ( 1/4 × 7 + 5)

simplify

5 × (1/4 ×12)

5 × 3

15 is thw answer

Answer: 7/8

Cos2x has 3 formulas, Sinx is given in the question, we should use the formula with sinus. I guess that's the solution.

Answer:

Cost of 1 goggles = $20

Cost of 1 mask = 15

Step-by-step explanation:

Given:

Cost of 2 goggles and 1 mask = $55

Cost of 1 goggles and 2 mask = $50

Find:

Cost of each goggles and mask

Computation:

Assume;

Cost of 1 goggles = a

Cost of 1 mask = b

So,

2a + b = 55.....EQ1

a + 2b = 50.......EQ2

EQ1 x 2

4a + 2b = 110 ......EQ3

EQ3 - EQ2

3a = 60

a = 20

Cost of 1 goggles = $20

a + 2a = 50

20 + 2b = 50

2b = 30

b = 15

Cost of 1 mask = 15

.

Answer:

I'm pretty sure it's the 3rd option

Answer:

first option is correct

Step-by-step explanation:

because there are less no. on negative side than on positive one

Answer:

x=2 is incorrect

Step-by-step explanation:

Y(2)=(3/4)*x^2=(3/4)*4=3

Answer:

m∠LMK = 50°

Step-by-step explanation:

This is an isosceles triangle. Isosceles triangles have two sides of equal length and two equal angles. This means ∠K and ∠M will have the same degrees.

The sum of the angles of a triangle is 180°. The following equation can be arranged and solved for the missing angles:

[tex]x+x+80=180\\2x+80=180\\2x=100\\x=50[/tex]

Therefore, m∠LMK = 50°.

Consider this example: say we want to convert x = 11 0101 1001₂ to base 3.

The binary expansion of x is

x = 1×2⁹ + 1×2⁸ + 1×2⁶ + 1×2⁴ + 1×2³ + 1×2⁰

which in base 10 reduces to

x = 512 + 256 + 64 + 16 + 8 + 1 = 857

Recall the first several powers of 3:

3⁰ = 1; 3¹ = 3; 3² = 9; 3³ = 27; 3⁴ = 81; 3⁵ = 243; 3⁶ = 729

Now it's a matter of computing quotients and remainders. Pick the largest power of 3 that fits into the target number, then check the remainder and repeat.

• How many times does the 729 go into 857? 1 time, and it leaves a remainder of 128, or

857 = 1×729 + 128 = 1×3⁶ + 128

• How many times does 81 go into 128? Also 1 time, so

128 = 1×81 + 47 = 1×3⁴ + 47

• How many times does 27 go into 47? Also 1 time,

47 = 1×27 + 20 = 1×3³ + 20

• How many times does 9 go into 20? 2 times,

20 = 18 + 2 = 2×9 + 2 = 2×3² + 2

• How many times does 1 go into 2? Also 2 times,

2 = 2 + 1 = 2×1 + 0 = 2×3⁰

So we found

857 = 1×3⁶ + 1×3⁴ + 1×3³ + 2×3² + 2×3⁰

which is the ternary expansion of x,

x = 1 011 202₃

Answer:

[tex]{ \sf{ - 2 {a}^{5} + 4 {a}^{4} + 5 {a}^{3} + \frac{2}{3}a }}[/tex]

Answer:

D

Step-by-step explanation:

A polynomial is in standard equation when the degree of the polynomial are in descending order.

Answer:

Step-by-step explanation: Scale [tex]\frac{130}{100} = \frac{13}{10}[/tex]

New dimensions [tex]16 * 1.3 --- 24*1.3 =20.8 cm * 31.2 cm[/tex]

Answer: (a): Good course, (b): Bad course

Step-by-step explanation:

Firstly, because the standard deviation of the good course results is lower, there is less variation so he performs more consistently there.

Secondly, the trick with the second question is that while the mean of the bad course is slightly less, the standard deviation is quite a lot higher than that of the good course, so it's more likely that the highest single test score belongs to the bad course.

Answer:

Step-by-step explanation:

Applying the midpoint formula to the points (a, 0) and (0, a) looks like this:

[tex]M=(\frac{a+0}{2},\frac{0+a}{2})[/tex] which simplifies to

[tex]M=(\frac{a}{2},\frac{a}{2})[/tex]

Answer:

-6 and - 65

Step-by-step explanation:

X-12x-29, by completing the square we get (x-6)^2-65

Answer:

The rea of walk way is 32 ft^2.

Step-by-step explanation:

width, w = 8 feet

length, L = 10 feet

width of walkway, d = 2 feet

length of outer, L' = 10 + 2 + 2 = 14 feet

Area of outer, A' = L' x w = 14 x 8 = 112 ft^2

Area of inner, A = L x w = 10 x 8 = 80 ft^2

The area of walkway = A' - A = 112 - 80 = 32 ft^2

The rea of walk way is 32 ft^2.

Step-by-step explanation:

Given

x = 3/4

y = -2/5

Now

X + y = 3/4 - 2/5

[tex] \frac{3 \times 5 - 2 \times 4}{20} [/tex]

[tex] = \frac{15 - 8}{20} [/tex]

[tex] = \frac{7}{20} [/tex]

Answer:

7/20

Step-by-step explanation:

x=3/4

y= -2/5

x+y=?

to get the sum, plug in x=3/4 into the x and y= -2/5 into the y

1. x + y = ?

2. 3/4 + (- 2/5) = ?

3. 3/4 - 2/5 =?

4. find the lcm of 4 and 5 to get the common denominator (in this case, the lcm of 4 and 5 is 20)

5. multiply 3/4 by 5 (numerator and denominator) and 2/5 by 4 (numerator and denominator)

6. 15/20 - 8/20 = 7/20

the answer is 7/20