HALP ASAP!!! 10 POINTS

Josh estimates the height of his desk. what is the reasonable estimate?

Galina-37 [17]

<span>The complete question includes these choices: A)1 foot B)2 feet C)5 feet D)9 feet The correct answer is B) 2 feet, approx. 24 inches; most standard desks have a height between 28'' to 30''. The answer A is too low, C and D are too much, the perfect answer would be at least 3-4 feet, but as this question proposes only these answers, the nearest estimating value is B)2 feet. </span>

8 0

3 years ago

What is the slope of the line? Please help :)

Anuta_ua [19.1K]

Answer:

The slope of line is 2/3.

Step-by-step explanation:

To calculate slope you do :

y2 - y1 / x2 - x1

6 0

3 years ago

Read 2 more answers

How tall is a building that casts a 78-ft shadow when the angle of elevation of the sun is 30 degrees?

Marta_Voda [28]

Answer: $45.03\ ft$

Step-by-step explanation:

Given

The length of the shadow is 78 ft

the angle of elevation is $\theta =30^{\circ}$

Suppose the height of the building is $h$

From the figure, we can write

$\tan 30^{\circ}=\dfrac{h}{78}\\\\h=78\tan 30^{\circ}\\\\h=45.03\ ft$

The height of the building is 45.03 ft

8 0

2 years ago

What are the roots of the polynomial equation x^3-5x+5=2x^2-5? Use a graphing calculator and a system of equations. Round nonint

leonid [27]

The right answer is c. –2.24, 2, 2.24

This question needs to be solved in two ways. First, using a graphing calculator. Next, using a system of equations.

1. Using a graphing calculator.

We have the following polynomial equation:

$x^3-5x+5=2x^2-5$

By ordering this equation we have:

$x^3-2x^2-5x+10=0$

So, we can say that this equation comes from a function given by:

$f(x)=x^3-2x^2-5x+10$

Thus, by plotting this function, we have that the graph of this function is indicated in Figure 1. By zooming, we can see, in Figure 2, that the roots of the polynomial equation are the x-intercepts of $f(x)$ which are:

$x_{1}=-2.236 \\ \\ x_{2}=2 \\ \\ x_{3}=2.236$

Finally, rounding noninteger roots to the nearest hundredth we have:

$\boxed{Root_{1}=-2.24} \\ \\ \boxed{Root_{2}=2} \\ \\ \boxed{Root_{3}=2.24}$

2. Using a system of equations.

The ordered equation is:

$x^3-2x^2-5x+10=0$

By arranging to factor out we have:

$x^3-5x-2x^2+10=0$

Then, by factoring:

$x(x^2-5)-2(x^2-5)=0$

Term $(x^2-5)$ is a common factor, thus:

$(x-2)(x^2-5)=0 \\ \\ (x-2)(x-\sqrt{5})(x+\sqrt{5})=0 \\ \\ Finally: \\ \\ \boxed{Root_{1}=-\sqrt{5}=-2.24} \\ \\ \boxed{Root_{2}=2} \\ \\ \boxed{Root_{3}=\sqrt{5}=2.24}$

6 0

3 years ago

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Suppose you solved a second-order equation by rewriting it as a system and found two scalar solutions: y = e^5x and z = e^2x. Th

xenn [34]

Answer:

The solutions are linearly independent because the Wronskian is not equal to 0 for all x.

The value of the Wronskian is $\bold{W=-3e^{7x}}$

Step-by-step explanation:

We can calculate the Wronskian using the fundamental solutions that we are provided and their corresponding the derivatives, since the Wroskian is defined as the following determinant.

$W = \left|\begin{array}{cc}y&z\\y'&z'\end{array}\right|$

Thus replacing the functions of the exercise we get:

$W = \left|\begin{array}{cc}e^{5x}&e^{2x}\\5e^{5x}&2e^{2x}\end{array}\right|$

Working with the determinant we get

$W = 2e^{7x}-5e^{7x}\\W=-3e^{7x}$

Thus we have found that the Wronskian is not 0, so the solutions are linearly independent.

3 0

3 years ago