All categories

3 years ago

Find the sum of 3 - 7i and 8 + 4i. 11 - 3i 11 + 3i 22 - 8i -22 + 8i

Mathematics

2 answers:

klio [65]3 years ago

6 0

Answer:

11 -3i

First option is correct.

Step-by-step explanation:

We have to find the sum of the complex number 3 - 7i and 8 + 4i.

In adding two complex numbers, real part gets added with the real part and the imaginary part gets added with the imaginary part.

For the first complex numbers 3 - 7i, we have

real part = 3

imaginary part = -7i

For the second complex numbers 8 + 4i, we have

real part = 8

imaginary part = 4i.

Hence, the sum of the complex numbers is given by

3 - 7i + 8 + 4i

= (3+8) +(-7+4)i

= 11 -3i

First option is correct.

Debora [2.8K]3 years ago

5 0

3 - 7i + 8 + 4i = 3 + 8 - 7i + 4i = 11 - 3i.

The answer is A, 11-3i.

You might be interested in

Hi if you know 8th grd math pls help

Kryger [21]

Answer:

all correct except A.

Step-by-step explanation:

pls mark me brainly if u can

4 0

2 years ago

The initial population of a town is 2600, and it grows with a doubling time of 10 years. Determine how long it will take for the

choli [55]

Answer:

It will take the 20 years for the population to quadruple.

Step-by-step explanation:

Exponential population growth:

An exponential model for population growth has the following model:

$P(t) = P(0)(1+r)^t$

In which P(0) is the initial population and r is the growth rate, as a decimal.

It grows with a doubling time of 10 years.

This means that $P(10) = 2P(0)$ . We use this to find r. So

$P(t) = P(0)(1+r)^t$

$2P(0) = P(0)(1+r)^10$

$(1+r)^10 = 2$

$\sqrt[10]{(1+r)^10} = \sqrt[10]{2}$

$1+r = 2^{\frac{1}{10}}$

$1 + r = 1.0718$

$P(t) = P(0)(1+r)^t$

$P(t) = P(0)(1.0718)^t$

Determine how long it will take for the population to quadruple.

This is t for which P(t) = 4P(0). So

$P(t) = P(0)(1.0718)^t$

$4P(0) = P(0)(1.0718)^t$

$(1.0718)^t = 4$

$\log{(1.0718)^t} = \log{4}$

$t\log{1.0718} = \log{4}$

$t = \frac{\log{4}}{\log{1.0718}}$

$t = 20$

It will take the 20 years for the population to quadruple.

5 0

3 years ago

What are the roots of the function y = 4x2 + 2x – 30? To find the roots of the function, set y = 0. The equation is 0 = 4x2 + 2x

nasty-shy [4]

4x² + 2x - 30 = 0

factor out the GCF:
2(2x² + x - 15) = 0

factor the trinomial completely:
2x² + x - 15 = 0
2x² + 6x - 5x - 15 = 0
2x(x + 3) - 5(x + 3) = 0
(2x - 5)(x + 3) = 0

use the zero product property and set each factor equal to zero and solve:
2x - 5 = 0 or x + 3 = 0
2x = 5 x = -3
x = 2.5

The roots of the function are x=-3, x=2.5

8 0

3 years ago

Read 2 more answers

You have torn a tendon and are facing surgery to repair it. the surgeon explains the risks to you: the probability of infection

skad [1K]

P(most favorable outcome) = 1 -(0.03 +0.16 -0.01) = 0.82

_____
"repair fails" includes the "infection and failure" case, as does "infection". By adding the probability of "repair fails" and "infection", we count the "infection and failure" case twice. So, we have to subtract the probability of "infection and failure" from the sum of "repaire fails" and "infection" in order to count each bad outcome only once.

The probability of a good outcome is the complement of the probability of a bad outcome.

5 0

3 years ago

Find the area of an equilateral triangle (regular 3 Gon) with the given measurement 9 in perimeter a=SQ.in

blsea [12.9K]

Answer:

3.897 $in^{2}$

Step-by-step explanation:

equilateral triangles are also equiangular, meaning the have equal angles.

Triangle sum theory says that angles of a triangle add up to 180.

That means each angle is 60.

A = bh/2

You need the (h). The base of is 3. Perimeter = 9, so each side is 3

Draw a perpendicular line for the height. The line cuts the base in half (1.5)

Using trigonometry you can find the height.

tan 60° = h/1.5

h = height, 1.5 is half of 3, 60° is the base angle.

multiply each side by 1.5

1.5(tan 60°) = h

h=2.598

then substitute h into formula

A= (2.598)(3)

A = 3.897 rounded

4 0

3 years ago