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4 years ago

11

The 11th term in a geometric sequence is 48 and the common ratio is −0.8. The 12th term is ___ and the 10th term is

__.

1 answer:

Svetach [21]4 years ago

6 0

Answer:

The 12th term is <u>-38.4</u> and the 10th term is <u>-60</u>.

Step-by-step explanation:

Consider the geometric sequence,

$S=\{a,\ ar,\ ar^{2},\ ar^{3},\ ...\}$

The first term is, <em>a</em>.

The common ratio is, <em>r</em>.

The formula to compute the common ratio is:

$r=\frac{T_{n}}{T_{n-1}}$

The information provided is:

T₁₁ = 48

r = -0.8

Compute the 12th term as follows:

$r=\frac{T_{n}}{T_{n-1}}$

<em></em> $-0.8=\frac{T_{12}}{T_{11}}\\\\0.8=\frac{T_{12}}{48}\\\\T_{12}=48\times-0.8\\\\T_{12}=-38.4$ <em></em>

The 12th term of the geometric sequence is -38.4.

Compute the 10th term as follows:

$r=\frac{T_{n}}{T_{n-1}}$

<em></em> $-0.8=\frac{T_{11}}{T_{10}}\\\\0.8=\frac{48}{T_{10}}\\\\T_{10}=\frac{48}{-0.8}\\\\T_{10}=-60$ <em></em>

The 10th term of the geometric sequence is -60.

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Two skateboarders, Ron and Bob, are traveling in opposite directions.Ton travels at 8 feet per second and bob travels at 10 feet

omeli [17]

Time taken before they are 2640 feet is 146.67 seconds

<em><u>Solution:</u></em>

The distance is given by formula:

$distance = speed \times time$

<em><u>Ton travels at 8 feet per second</u></em>

Let us assume, time taken = t

speed = 8 feet per second

Then, distance is given as:

Distance covered by Ton = 8t

<em><u>Bob travels at 10 feet per second</u></em>

Then, distance is given as:

Distance covered by Bob = 10t

How long will it take before they are 2640 feet

Which means,

Distance covered by Ton + Distance covered by Bob = 2640

$8t + 10t = 2640\\\\18t = 2640\\\\Divide\ both\ sides\ of\ equation\ by\ 18\\\\t = 146.67$

Thus time taken before they are 2640 feet is 146.67 seconds

<h3><u>Method 2:</u></h3>

Since trains are moving in opposite directions, their speeds must be added

speed = 8 + 10 = 18 feet per second

Given distance = 2640 feet

Therefore, time taken is:

$time = \frac{distance}{speed}\\\\time = \frac{2640}{18} = 146.67 \text{ second }$

Thus time taken before they are 2640 feet is 146.67 seconds

4 0

4 years ago

Need help please!! i will mark brainliest to whoever answers correctly <33

sergij07 [2.7K]

Answer:

x = -33

Step-by-step explanation:

To find the midpoint add the two points and divide by 2

(x+27)/2 = -3

Multiply each side by 2

(x+27)/2 *2= -3*2

x+27 = -6

Subtract 27 from each side

x+27-27 = -6 -27

x = -33

4 0

3 years ago

In a Match 6 Lotto, winning the jackpot requires that you select six different numbers from 1 to 49, and that the same six numbe

zimovet [89]

Answer:

$P=\frac{1}{13,983,816}=7.2\ x\ 10^{-8}$

Step-by-step explanation:

Consider the following characteristics of the problem:

The numbers that are selected are different between 1 and 49. This means that the same number is not repeated twice.

The order in which the selected numbers appear does not matter:

This means that (123) = (312)

With this in mind, we know that it is a problem of combinations without repetition. It is not calculated using permutations because in the permutations the order of selection is important, for example: (123) is not equal to (312)

The formula for calculating combinations without repetition is:

$nCr=\frac{n!}{r!(n-r)!}$

Where n is the number of "elements" you can choose and choose r from them

In this case:

n=49

r=6

So:

$49C6=\frac{49!}{6!(49-6)!}$

$49C6=13,983,816\ outcomes$

There are 13,983,816 possible results

This is the best method to calculate the number of possible outcomes.

<em><u>"Besides your method, is there another method to determine the number of outcomes?"</u></em>

Sure, make a list of the 13,983,816 different sets of 6 numbers.

To win it is necessary to obtain the 6 winning numbers in any order. The number of ways this can occur is calculated by combining 6 in 6

$6C6=\frac{6!}{6!(6-6)!}=1$

Finally the probability of winning is:

$P=\frac{1}{13,983,816}=7.2\ x\ 10^{-8}$

Note that the probability of winning is very close to 0. It is practically impossible to win the lottery, you will probably never win anything. Therefore it is better not to invest money in this

6 0

3 years ago

How to determine if the columns of a matrix are linearly independent?

astra-53 [7]

Let's consider an arbitrary 2x2 matrix as an example,

$\mathbf A=\begin{bmatrix}\mathbf x&\mathbf y\end{bmatrix}=\begin{bmatrix}x_1&y_1\\x_2&y_2\end{bmatrix}$

The columns of $\mathbf A$ are linearly independent if and only if the column vectors $\mathbf x,\mathbf y$ are linearly independent.

This is the case if the only way we can make a linear combination of $\mathbf x,\mathbf y$ reduce to the zero vector is to multiply the vectors by 0; that is,

$c_1\mathbf x+c_2\mathbf y=\mathbf 0$

only by letting $c_1=c_2=0$ .

A more concrete example: suppose

$\mathbf A=\begin{bmatrix}1&2\\4&8\end{bmatrix}$

Here, $\mathbf x=\begin{bmatrix}1\\4\end{bmatrix}$ and $\amthbf y=\begin{bmatrix}2\\8\end{bmatrix}$ . Notice that we can get the zero vector by taking $c_1=-2$ and $c_2=1$ :

$-2\begin{bmatrix}1\\4\end{bmatrix}+\begin{bmatrix}2\\8\end{bmatrix}=\begin{bmatrix}-2+2\\-8+8\end{bmatrix}=\mathbf 0$

so the columns of $\mathbf A$ are not linearly independent, or linearly dependent.

8 0

3 years ago

The angular velocity of a fan blade is 6.2 radians per second.

MA_775_DIABLO [31]

Answer:

94.7 revolutions

Step-by-step explanation:

In the question above, we are given the following values for the fan

Angular velocity = 6.2 radians per seconds

Time = 1.6 minutes.

Step 1

We would convert the time given to seconds

1 minute = 60 seconds

1.6 minutes = ?

We cross multiply

1.6 minutes × 60 seconds

= 96 seconds

Step 2

Number of revolutions made by the fan is calculated as :

Angular velocity(rad/s)

× time(seconds)

Number of revolutions = 6.2 radians per seconds × 96 seconds

=595.2 radians

Converting from radians to revolution

1 radian = 0.159155 revolutions

595.2 radians =

Cross multiply

= 595.2 radians × 0.159155 revolutions

= 94.729056 revolutions.

Approximately to the nearest tenth = 94.7 revolutions.

Therefore, the number of revolutions the fan blade makes in 1.6 minutes is 94.7 revolutions.

8 0

3 years ago