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2 years ago

Evaluate the expression 1 + 3 i/5 i and write the result in the form a + b i .

Mathematics

1 answer:

polet [3.4K]2 years ago

8 0

Answer: $\bold{\dfrac{3}{5}-\dfrac{1}{5}}i$

Step-by-step explanation:

Rationalize the denominator. Then separate into the a & b-components.

$\dfrac{1+3i}{5i}\bigg(\dfrac{i}{i}\bigg)\quad =\quad \dfrac{i+3i^2}{5i^2}\quad =\quad \dfrac{i+3(-1)}{5(-1)}\quad =\quad \dfrac{i-3}{-5}\quad =\quad \dfrac{3-i}{5}\\\\\\=\large\boxed{\dfrac{3}{5}-\dfrac{1}{5}i}$

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Just need the answer for a and b

34kurt

Answer:

2⁵× 2ˣ = 256

x= 3

(1/3)² (1/3)ˣ = 1/729

x= 4

Step-by-step explanation:

2⁵× 2ˣ = 256

x= 3

use Product Rule: xᵃxᵇ=xᵃ⁺ᵇ

convert both sides to the same base.

2⁵⁺ˣ = 2⁸

cancel the base of 2 on both sides.

5+x=8

subtract 5 from both sides.

x=8-5

simplify 8-5 3.

x=3

(1/2)² (1/3)ˣ = 1/729

x = 4

use division distributive property: (x/y)ᵃ=xᵃ/yᵃ

i hope this helped i didn't feel like typing the rest out though lol :(

5 0

2 years ago

I need help on this quick

Pachacha [2.7K]

Answer:

The hypotenuse to the nearest tenth is 8.1

Step-by-step explanation:

We can use the Pythagorean theorem to solve

a^2 + b^2 = c^2 where a and b are the legs and c is the hypotenuse

Let a be the x leg and b be the y leg

a = 7 units

b= 4 units

7^2 + 4^2 = c^2

49+ 16 = c^2

65 = c^2

Take the square root of each side

sqrt(65) = sqrt(c^2)

8.062257748 =c

To the nearest tenth

8.1 =c

7 0

2 years ago

140 fluid ounces increased by 45%

Radda [10]

$100\%\ increased\ by\ 45\%=100\%+45\%=145\%\\\\method\ \#1\\\\p\%=\frac{p}{100}\to145\%=\frac{145}{100}=\frac{145:5}{100:5}=\frac{29}{20}\\\\145\%\ of\ 140=\frac{29}{20}\cdot140=29\cdot7=\boxed{203\ (ounces)}\leftarrow answer$

$method\ \#2\\\\\begin{array}{ccc}140&-&100\%\\x&-&145\%\end{array}\ \ \ cross\ multiply\\\\\\100\cdot x=140\cdot145\ \ \ \ |divide\ both\ sides\ by\ 100\\\\x=\frac{140\cdot145}{100}\\\\\boxed{x=203\ (ounces)}$

4 0

3 years ago

A website manager has noticed that during the evening hours, about 5 people per minute check out from their shopping cart and m

Over [174]

Answer:

a) Poisson distribution

b) 99.33% probability that in any one minute at least one purchase is made

c) 0.05% probability that seven people make a purchase in the next four minutes

Step-by-step explanation:

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:

$P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}$

In which

x is the number of sucesses

e = 2.71828 is the Euler number

$\mu$ is the mean in the given time interval.

5 people per minute check out from their shopping cart and make an online purchase.

This means that $\mu = 5$

a) What model might you suggest to model the number of purchases per minute? 

The only information that we have is the mean number of an event(purchases) in a time interval. Each event is also independent fro each other. So you should suggest the Poisson distribution to model the number of purchases per minute.

b) What is the probability that in any one minute at least one purchase is made? 

Either no purchases are made, or at least one is. The sum of the probabilities of these events is 1. So

$P(X = 0) + P(X \geq 1) = 1$

We want to find $P(X \geq 1)$

$P(X \geq 1) = 1 - P(X = 0)$

In which

$P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}$

$P(X = 0) = \frac{e^{-5}*(5)^{0}}{(0)!} = 0.0067$

1 - 0.0067 = 0.9933.

99.33% probability that in any one minute at least one purchase is made

c) What is the probability that seven people make a purchase in the next four minutes?

The mean is 5 purchases in a minute. So, for 4 minutes

$\mu = 4*5 = 20$

We have to find P(X = 7).

$P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}$

$P(X = 0) = \frac{e^{-20}*(20)^{7}}{(7)!} = 0.0005$

0.05% probability that seven people make a purchase in the next four minutes

8 0

3 years ago

The vertex of this parabola is at (-3, -1). When the y-value is 0, the x-value is 4. What is the coefficient of the squared term

Ivanshal [37]

Hello :
the parabola's equation is : f(x) = a(x+3)²-1
the coefficient of the squared expression in the parabola's equation is : a
but ; f(4) = 0
0 = a(4+3)²-1
49a-1=0.....a=1/49
f(x) = 1/49(x-3)²-2

5 0

3 years ago