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2 years ago

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PLEASE HELP NOWWW!!!!!! A country consists of two islands. The population of birds on one island is 1.105 million, and the popul

ation of birds on the other island is 2.21 million. Which expression finds the population of birds for this country?
1. 1.105 million + 2.021 million
2. 1.15 million + 2.21 million
3. 1.105 million + 2.201 million
4. 1.105 million + 2.210 million

2 answers:

marysya [2.9K]2 years ago

8 0

Answer:

It's D

Step-by-step explanation:

I did the same thing.

sorry if this doesn't help!! I tried..

wlad13 [49]2 years ago

5 0

the answer is 1.. I know this because im in seventh grade

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PLEASEEE HELPPPP ASAPPPP

stellarik [79]

$\cos 27^{\circ} = \dfrac{KL}x\\\\\implies \cos 27^{\circ} = \dfrac{6.3}x\\\\\implies x = \dfrac{6.3}{\cos 27^{\circ}}=7.1~ \text{units.}$

6 0

1 year ago

A tree 10 meters high casts a 17.3 meter shadow.

sashaice [31]

Answer:

the angle of elevation of the sun is $\approx 30^o$

Step-by-step explanation:

Let's make a diagram of the tree, ground and inclination of the rays of the sun, so we understand what right angle triangle we have. Please see the attached image.

Notice that our unknown is the angle $\theta$ , and that we know the size of the side opposite to it, and of the side adjacent to it. Therefore the most convenient trigonometric formula to use is the tangent of the angle because:

$tan(\theta)=\frac{opposite}{adjacent} \\tan(\theta)=\frac{10}{17.3}\\\theta=arctan(\frac{10}{17.3})\\\theta\approx 30^o$

5 0

3 years ago

the function intersects its midline at (-pi,-8) and has a maximum point at (pi/4,-1.5) write an equation

Tcecarenko [31]

The equation that represents the <em>sinusoidal</em> function is $x(t) = -8 + 6.5 \cdot \sin \left[\left(\frac{2}{3} \pm \frac{4\cdot i}{3}\right)\cdot t + \left(\frac{2\pi}{3} \pm \frac{7\pi \cdot i}{3} \right)\right]$ , $i\in \mathbb{Z}$ .

<h3>Procedure - Determination of an appropriate function based on given information</h3>

In this question we must find an appropriate model for a <em>periodic</em> function based on the information from statement. <em>Sinusoidal</em> functions are the most typical functions which intersects a midline ( $x_{mid}$ ) and has both a maximum ( $x_{max}$ ) and a minimum ( $x_{min}$ ).

Sinusoidal functions have in most cases the following form:

$x(t) = x_{mid} + \left(\frac{x_{max}-x_{min}}{2} \right)\cdot \sin (\omega \cdot t + \phi)$ (1)

Where:

$\omega$ - Angular frequency
$\phi$ - Angular phase, in radians.

If we know that $x_{min} = -14.5$ , $x_{mid} = -8$ , $x_{max} = -1.5$ , $(t, x) = (-\pi, -8)$ and $(t, x) = \left(\frac{\pi}{4}, -1.5 \right)$ , then the sinusoidal function is:

$-8 +6.5\cdot \sin (-\pi\cdot \omega + \phi) = -8$ (2)

$-8+6.5\cdot \sin\left(\frac{\pi}{4}\cdot \omega + \phi \right) = -1.5$ (3)

The resulting system is:

$\sin (-\pi\cdot \omega + \phi) = 0$ (2b)

$\sin \left(\frac{\pi}{4}\cdot \omega + \phi \right) = 1$ (3b)

By applying <em>inverse trigonometric </em>functions we have that:

$-\pi\cdot \omega + \phi = 0 \pm \pi\cdot i$ , $i \in \mathbb{Z}$ (2c)

$\frac{\pi}{4}\cdot \omega + \phi = \frac{\pi}{2} + 2\pi\cdot i$ , $i \in \mathbb{Z}$ (3c)

And we proceed to solve this system:

$\pm \pi\cdot i + \pi\cdot \omega = \frac{\pi}{2} \pm 2\pi\cdot i -\frac{\pi}{4}\cdot \omega$

$\frac{3\pi}{4}\cdot \omega = \frac{\pi}{2}\pm \pi\cdot i$

$\omega = \frac{2}{3} \pm \frac{4\cdot i}{3}$ , $i\in \mathbb{Z}$ $\blacksquare$

By (2c):

$-\pi\cdot \left(\frac{2}{3} \pm \frac{4\cdot i}{3}\right) + \phi =\pm \pi\cdot i$

$-\frac{2\pi}{3} \mp \frac{4\pi\cdot i}{3} + \phi = \pm \pi\cdot i$

$\phi = \frac{2\pi}{3} \pm \frac{7\pi\cdot i}{3}, i\in \mathbb{Z}$ $\blacksquare$

The equation that represents the <em>sinusoidal</em> function is $x(t) = -8 + 6.5 \cdot \sin \left[\left(\frac{2}{3} \pm \frac{4\cdot i}{3}\right)\cdot t + \left(\frac{2\pi}{3} \pm \frac{7\pi \cdot i}{3} \right)\right]$ , $i\in \mathbb{Z}$ . $\blacksquare$

To learn more on functions, we kindly invite to check this verified question: brainly.com/question/5245372

5 0

2 years ago

What is three fourths plus five eighths

natima [27]

One and three eighths. Or eleven eighths.

5 0

2 years ago

Read 2 more answers

Brainliest to correct answer

Gnesinka [82]

Question 1:

For this case we must factor the following expression:

$n ^ 2 + 2n-24 = 0$

We must find two numbers that when multiplied result in -24 and when added together result in 2. These numbers are: 6 and -4.

$6*(-4)=-24\\6-4=2$

Thus, we factor:

$(x + 6) (x-4) = 0$

The roots are:

$x_ {1} = - 6\\x_ {2} = 4$

Answer:

Option C

Question 2:

For this case we have that by definition, the area of a rectangle is given by:

$A = w * l$

Where:

w: Is the width of the rectangle

l: is the length of the rectangle

According to the statement we have:

$A = 30 \ ft ^ 2\\l = 3w-1$

Substituting:

$(3w-1) w = 30\\3w ^ 2-w = 30\\3w ^ 2-w-30 = 0$

Where:

$a = 3\\b = -1\\c = -30$

The solution:

$x = \frac {-b \pm \sqrt {b ^ 2-4 (a) (c)}} {2a}\\x = \frac {- (- 1) \pm \sqrt {(- 1) ^ 2-4 (3) (- 30)}} {2 (3)}\\x = \frac {1 \pm \sqrt {1 + 360}} {2 (3)}\\x = \frac {1 \pm \sqrt {361}} {6}\\x = \frac {1\pm19} {6}\\$

We have two roots:

$x_ {1} = \frac {1-19} {6} = \frac {-18} {6} = - 3\\x_ {2} = \frac {1 + 19} {6} =\frac {20} {6} = 3,333$

We choose the second value (the positive), when rounding is $3.33 \ ft$

Answer:

Option A

4 0

3 years ago