Gio is solving the quadratic equation by completing the square 5x^2+15x-4=0 What's should gio do first?

In aΔABC, if ∠B = 60° and the ratio of two sides is a : c = 2 : √3 + 1, then ∠A= ____.

bekas [8.4K]

To calculate for the value of ∠ A, let us first find for the length of side B using the cosine law:

b^2 = a^2 + c^2 – 2 a c cos B

b^2 = 2^2 + (√3 + 1)^2 – 2 (2) (√3 + 1) cos 60

b^2 = 6

b = 2.45

Given two sides and the angle in between, we can calculate for ∠A using the sine law:

b / sin B = a / sin A

2.45 / sin 60 = 2 / sin A

sin A = 0.707

A = 45˚

Therefore the answer is letter A: 45

8 0

2 years ago

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A marine biologist is setting up a net 6 feet below the surface of the water. Each foot of the water screens out 40% of the ligh

rosijanka [135]

Answer:

The correct answer is C. 4.7%

Correct statement and question:

A marine biologist is setting up a net 6 feet below the surface of the water. Each foot of the water screens out 40% of the light coming from the surface. Which of the following is the approximate percentage of light remaining after passing through 6 feet of water, to the nearest tenth of a percent?

0.4%

1.0%

4.7%

7.8%

Source: brainly.com/question/4136163

Step-by-step explanation:

1. Let's review all the information given to us to answer the question correctly:

Depth of the net = 6 feet below the surface of the water

Each foot of the water screens out 40% of the light coming from the surface.

2. Which is the approximate percentage of light remaining after passing through 6 feet of water, to the nearest tenth of a percent?

After one feet: 100 - 40 = 60%

After two feet = 60 - 0.4 * 60 = 60 - 24 = 36

After three feet = 36 - 0.4 * 36 = 36 - 14.4 = 21.6

After four feet = 21.6 - 0.4 * 21.6 = 21.6 - 8.64 = 12.96

After five feet = 12.96 - 0.4 * 12.96 = 12.96 - 5.18 = 7.78

After six feet = 7.78 - 0.4 * 7.78 = 7.78 - 3.11 = 4.67 = 4.7 (Rounding to the nearest tenth)

The correct answer is C. 4.7%

5 0

2 years ago

At UF, there are always a few days between the end of classes and the beginning of final exams. These days are meant as a study

Natalija [7]

Answer:

This sample is not representative of all UF students, since those who are not local are not considered.

Step-by-step explanation:

This is a common statistics practice, when we want to study something from a population, we find a sample of this population.

However, the sample has to be representative

For example:

I want to estimate the proportion of New York state residents who are Buffalo Bills fans. So i ask, lets say, 1000 randomly selected Buffalo residents wheter they are Buffalo Bills fans, and expand this to the entire population of New York State residents. This is not representative of all New York State residents, just Buffalo residents.

In this problem, we have that:

They conduct a phone survey (with local numbers selected at random from the student directory) calling people during "dead week". Will this sample be representative of all UF students?

They only call those students with local numbers.

However, in an university, it is expected that there will be a good percentage of non local students.

So this sample is not representative of all UF students, since those who are not local are not considered.

8 0

2 years ago

An archeologist discovers the two artifacts shown. a. What integer represents ground level?

sweet [91]

If you add more detail i might be able to help you?

5 0

2 years ago

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a student concluded that the solution to the equation sqrt 2x+1+3=0 is x=4 Do you agree? Explain why or why not.