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3 years ago

What is the nth term of the quadratic sequence 7 , 14 , 23 , 34 , 47 , 62 , 79?

Mathematics

2 answers:

Harrizon [31]3 years ago

4 0

are you asking for the 9th term or the 10th term?

matrenka [14]3 years ago

4 0

First difference in the sequence is:-

7 9 11 13 15 17

second difference = 2 so nth term contains n2

subtracting n^2 from the sequence

7 14 23 34 47

1 4 9 16 25

= 6 10 14 18 22 this is an AP with first term 6 and common diff = 4

so formula is n^2 + ( 6 + 4(n - 1)

= n^2 + 4n + 2 answer

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Suppose that theta is an angle in standard position whose terminal side Intersects the unit circle at (-11/61, -60/61)

Blizzard [7]

Answer:

The exact values of the tangent, secant and cosine of angle theta are, respectively:

$\cos \theta = -\frac{11}{61}$

$\tan \theta = \frac{-\frac{60}{61} }{-\frac{11}{61} } = \frac{60}{11}$

$\sec \theta = \frac{1}{-\frac{11}{61} } = -\frac{61}{11}$

Step-by-step explanation:

The components of the unit vector are $x = -\frac{11}{61}$ and $y = -\frac{60}{61}$ . Since $r = 1$ , then $x = \cos \theta$ and $y = \sin \theta$ . By Trigonometry, tangent and secant can be calculated by the following expressions:

$\tan \theta = \frac{\sin \theta}{\cos \theta} = \frac{y}{x}$

$\sec \theta = \frac{1}{\cos \theta} = \frac{1}{x}$

Now, the exact values of the tangent, secant and cosine of angle theta are, respectively:

$\cos \theta = -\frac{11}{61}$

$\tan \theta = \frac{-\frac{60}{61} }{-\frac{11}{61} } = \frac{60}{11}$

$\sec \theta = \frac{1}{-\frac{11}{61} } = -\frac{61}{11}$

3 0

3 years ago

Cuanto es r2-2r-7=0

vekshin1

Answer:

Step-by-step explanation:

The solution is attached

6 0

3 years ago

Can someone help me and explain how to do it.

skelet666 [1.2K]

Answer:

uhhhhhhh you have to figure out what x is then choose wether it is the other variable a dependent variable, and explanatory variable, or a response variable

Step-by-step explanation:

easy as that

4 0

3 years ago

In his free time, Gary spends 13 hours per week on the Internet and 13 hours per week playing video games. If Gary has five hour

goldenfox [79]

<span>Gary spend 13 hours per week on the Internet and 13 hours on video games Gary has 5 hours of free time each day,
so total free time in a week=> 7*5=35 hours
Now he spends 13+13 hours on the internet and games=28 hours Percentage free time spent on games and internet

26/35 (that is a fraction) x100 =</span><span>74.285714
</span>so round your answer

6 0

3 years ago

Suppose that a brand of lightbulb lasts on average 1730 hours with a standard deviation of 257 hours. Assume the life of the lig

Debora [2.8K]

Answer:

P [ 1689 ≤ X ≤ 2267 ] = 54,88 %

Step-by-step explanation:

Normal Distribution

Mean μ₀ = 1730

Standard Deviation σ = 257

We need to calculate z scores for the values 1689 and 2267

We apply formula for z scores

z = ( X - μ₀ ) /σ

X = 1689 then

z = (1689 - 1730)/ 257 ⇒ z = - 41 / 257

z = - 0.1595

And from z table we get for z = - 0,1595

We have to interpolate

- 0,15 0,4364

- 0,16 0,4325

Δ = 0.01 0.0039

0,1595 - 0,15 = 0.0095

By rule of three

0,01 0,0039

0,0095 x ?? x = 0.0037

And 0,4364 - 0.0037 = 0,4327

Then P [ X ≤ 1689 ] = 0.4327 or P [ X ≤ 1689 ] = 43,27 %

And for the upper limit 2267 z score will be

z = ( X - 1730 ) / 257 ⇒ z = 537 / 257

z = 2.0894

Now from z table we find for score 2.0894

We interpolate and assume 0.9815

P [ X ≤ 2267 ] = 0,9815

Ths vale already contains th value of P [ X ≤ 1689 ] = 0.4327

Then we subtract to get 0,9815 - 0,4327 = 0,5488

Finally

P [ 1689 ≤ X ≤ 2267 ] = 0,5488 or P [ 1689 ≤ X ≤ 2267 ] = 54,88 %

8 0

3 years ago