Which expression will help you find the area of the triangular bases?

The Doppler shift was first tested in 1845 by the French scientist B. Ballot. He had a trumpet player sound a 455 Hz note while

White raven [17]

Answer:

2.9891

Step-by-step explanation:

Data provided in the question:

Frequency observed by observer, f₀ = 455 Hz

Beats heard by the Ballot = 3 beats/s

Now,

Speed of the sound, V = 343 m/s

Also,

Beats heard = $\left |\frac{f_0\times V}{V-v}-f_0\right|$

here,

v is the speed of the train moving towards the observer

thus,

4 = $\left |\frac{455\times 343}{343-v}-455\right|$

or

$\frac{455\times 343}{343-v}$ = 4 + 455

or

156065 = 459( 343 - v)

or

340.0109 = 343 - v

or

v = 343 - 340.0109

v = 2.9891

6 0

3 years ago

An article in Information Security Technical Report ["Malicious Software—Past, Present and Future" (2004, Vol. 9, pp. 6–18)] pro

olchik [2.2K]

Answer:

a) 99.9999%

b) 98.5938%

c) 9.26

d) 2.23

Step-by-step explanation:

A="at least one instance is Klez"

B="Five or more instances are Klez"

Xi={1 if The i-th instance is Klez, 0 else}

Y=Bin(20, 0.463)

a) $P(A)=P(Y\geq 1 )=1-P(Y=0)=1-P(\displaystyle\bigcap_{i=1}^{20}{X_i=1})=1- P(\displaystyle\sum_{i=1}^{20}X_i=20)=1- \displaystyle\prod_{i=1}^{20} P(X_i=1)=1-P(X_i=1)^{20}=1-0.4630^{20}=0.9999$

b) $P(B)=P(Y\geq 5)=1-P(Y$

$P(B)=1-\displaystyle\sum_{n=0}^{4}(^{20}_n)(0.4630)^n(1-0.4630)^{20-n} = 1-(3.9763\times10^{-6}+6.8568\times10^{-5}+5.6163\times10^{-4}+2.9054\times10^{-3}+0.0106)=0.9859$

c) $E[Y]=20\times0.463=9.26$

d) $Var(Y)=20\times0.463\times(1-0.463)=4.97, \sigma=\sqrt{4.97}=2.23$

7 0

4 years ago

Write the ratios in simplest form: 1. 10/15 2. 21 to 14 3. 15:25

mote1985 [20]

Answer:

1. 2/3

2. 3 to 2

3. 3:5

Step-by-step explanation:

1.

10/15 divide by 5

10/15 = 2/3

2.

21 to 14 divide by 7

21 to 14 = 3 to 2

3.

15:25 divide by 5

15:25 = 3:5

7 0

2 years ago

Read 2 more answers

In the solution of the equation 5 + 3x = -2x + 9, 2x is added to the equation first. Which of the following should be done next?

puteri [66]

You should subtract 5 from both sides next.

Adding 2x to both side will give you the following.

5 + 5x = 9

And since you got all the variable terms to the left, you want all the constant terms to the right. You do that by subtracting 5 from both sides. This gives you the below statement.

5x = 4

You can then divide to solve.

x = 4/5 or .8

5 0

3 years ago

determine whether the statement is true or false. If it is true, explain why. If it is false, explain why or give a counterexamp

Andrews [41]

Answer:

FALSE

Step-by-step explanation:

No, they are not

Counter-example:

Take t = 4

If r1 and r2 were the same curve, there should exist some value $\bf\large t^*$ for which

$\bf\large 4=3cos(t^*)$

Taking the absolute value on both sides

$\bf\large | 4 |=|3cos(t^*)|\Rightarrow 4=3|cos(t^*)|\leq 3$

since the function cos(x) takes values between -1 and 1.

But 4 is greater than 3, and we have a contradiction.

So, r1 and r2 are not the same curve.

8 0

3 years ago