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3 years ago

Math Q 8

1 answer:

4 0

If you have to do 70% of your projects and you have 3, you can approach this problem by showing that each project is 33.3% (I did 100/3 to determine what percentage each project is worth).

If we do one project, 33.3% is completed
If we do two projects, 66.6% is completed
If we do three projects, 100% is completed

Since we have to do at least 70%, we must do all three projects.

You might be interested in

Solve the differential equation by variation of parameters. y''+y=secx

suter [353]

Answer:y=

Acosx+Bsinx +cosx ln(cosx)+x sinx

Step-by-step explanation:

given equation y''+y=secx

auxiliary equation

$p^2+1=0\\p=\pm i$

so CF is y=Acosx+Bsinx

now

$y_1(x)=cosx \ \ \ \ y_2(x)=sinx\\{y_1}'(x)=-sinx \ \ \ \ {y_2}'(x)=cosx$

using wronskian formula

$W=\begin{vmatrix}cosx &sinx \\ -sinx & cosx\end{vmatrix}$

= $cos^2x+sin^2x=1$

now f(x)=secx

$u=-\int \frac{f(x)y_2(x)}{W(x)}dx \ and \ v=\int \frac{f(x)y_1(x)}{W(x)}dx$

$u=-\int \frac{secx\times sinx}{1}dx \ and \ v=\int \frac{secx\times cosx}{1}dx$

$u=-\int tanx dx \ and \ v=\int {1}dx$

$u=ln(cosx) \ \ \ and \ \ v=x$

now particular integrals are

PI=cosx ln(cosx)+x sinx

total solution

y= C.F+P.I

y=Acosx+Bsinx +cosx ln(cosx)+x sinx

8 0

4 years ago

The shadow of a tree measures 25 feet from its base. The angle of elevation to the Sun is 31º How tall is the tree? Round your a

grigory [225]

Answer: 15 feet

Step-by-step explanation:

Hi, since the situation forms a right triangle (see attachment) we have to apply the next trigonometric function.

Tan α = opposite side / adjacent side

Where α is the angle of elevation to the sun, , the opposite side (x) is the height of the tree, and the adjacent side is the length of the shadow.

Replacing with the values given:

Tan 31 = x /25

Tan 31 (25) =x

x = 15 feet

Feel free to ask for more if needed or if you did not understand something.

4 0

4 years ago

9x9= 8x8= 8x7= 5x4= Vă rog să mă ajutați

sergiy2304 [10]

Answer:

9×9=72

8×8=64

8×7=56

5×4=20

4 0

3 years ago

Read 2 more answers

The scores on a test for a sample of 42 statistics students are summarized in the following table. 9, 90, 18, 80, 15, 70. Find t

igomit [66]

<h3>Answer: 78.6</h3>

Work Shown:

$\begin{array}{|c|c|} \cline{1-2}\text{Number of People} & \text{Score}\\\cline{1-2}9 & 90\\\cline{1-2}18 & 80\\\cline{1-2}15 & 70\\\cline{1-2}\end{array}$

Multiply across the rows to form a third column. Example: 9*90 = 810 in the first row.

$\begin{array}{|c|c|c|} \cline{1-3}\text{Number of People} & \text{Score} & \text{Number*Score}\\\cline{1-3}9 & 90 & 810\\\cline{1-3}18 & 80 & 1440\\\cline{1-3}15 & 70 & 1050\\\cline{1-3}\end{array}$

The values in the third column add to 810+1440+1050 = 3300

Divide this over the total number of people which is 9+18+15 = 42

The mean is 3300/42 =78.571 approximately which rounds to 78.6

5 0

2 years ago

Someone help, I suck at math

attashe74 [19]

option A.55°

Answer:

Solution given:

<x+<y=<z

exterior angle of a triangle is equal to the sum of two opposite interior angle

4n-18+n+8=133-6n

5n+6n=133+10

11n=143

n=143/11

n=13

exterior angle =133-6*13=55°

option A.55°

5 0

3 years ago