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3 years ago

Find S15 for the series -1 + -3 + -5 + -7 +...

1 answer:

Ber [7]3 years ago

8 0

Hello :
the sum is arithmetic secquence of common -diff is :
(-7)-(-5) =(-5)-(-3) = (-3)-(-1) =-2 = d
the first term is : a1 = -1
the formula of the sum : S= (n/2)(a1 +an)
n is number of term an = a1+(n-1)d

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Cuanto es 100+100+0+0+0+0+0

jeka94

Answer:

es 200

Step-by-step explanation:

100+100=200

0+0+0+0+0=0

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3 years ago

Given the below sequence:

kvasek [131]

Answer:

a) The next three terms are -1,-3,-5,-7,-9,-11,-13

b) This is arithmetic sequence

C) The difference of second term and first term is -2 in given sequence so the given sequence is an arithmetic sequence.

d) The 27 th term is -53

Step-by-step explanation:

a) the given sequence is arithmetic sequence

the difference of second term and first term is -2

given sequence is -1,-3,-5,-7.....

the nth term in arithmetic sequence

$t_{n} = a+(n-1)d$

First term is a = -1 and difference is d = -2

finding fifth term is

$t_{5} = -1 +(5-1)(-2)$

$t_{5} = -1-8 =-9$

finding sixth term is

$t_{6} = -1 +(6-1)(-2)$

$t_{6} = -1-10 =-11$

finding seventh term is

$t_{7} = -1 + (7-1)(-2)$

$t_{7} = -1 -12 =-13$

The next three terms are -9,-11,-13

The given sequence is -1,-3,-5,-7,-9,-11,-13

b) This is arithmetic sequence.

C) because the difference of second term and first term is -2 so the given sequence is arithmetic sequence.

d) by using nth term formula in arithmetic sequence

$t_{n} = a+(n-1)d$

a= -1 and d =-2

find 27 t h term :-

$t_{27} = -1 + (27-1)(-2) = -1-52=-53$

6 0

3 years ago

Penelope has $1,459.75 in her bank account. To pay her bills, she writes 4 checks for $200.25, $359.45, $125, and $299.35. Then

sammy [17]

1,459.75 - 200.25 - 359.45 - 125.00 - 299.35 = 475.70

475.70 + 375.00 = 850.70

Her account balance after the bills and deposit is $850.70

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3 years ago

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Cos(−θ)=√3/3, sinθ<0

Delicious77 [7]

Answer:

$\sin\theta=-\frac{\sqrt{6}}{3}$

Step-by-step explanation:

The given trigonometric equation is $\cos(-\theta)=\frac{\sqrt{3} }{3}$ .

We can either use the Pythagorean identity or the right angle triangle to solve for $\sin\theta$ .

According to the Pythagorean identity,

$\cos^2\theta+\sin^2\theta=1$

Recall that, the cosine function is an even function, therefore

$\cos(-\theta)=\cos(\theta)$

$\Rightarrow \cos(\theta)=\frac{\sqrt{3} }{3}$ .

We substitute this value in to the above Pythagorean identity to get;

$(\frac{\sqrt{3}}{3})^2+\sin^2\theta=1$

$\Rightarrow \frac{3}{9}+\sin^2\theta=1$

$\Rightarrow \sin^2\theta=1-\frac{3}{9}$

$\Rightarrow \sin^2\theta=\frac{6}{9}$

$\Rightarrow \sin\theta=\pm \sqrt{\frac{6}{9}}$

$\Rightarrow \sin\theta=\pm \frac{\sqrt{6}}{3}$

But we were given that,

$\sin\theta\:$ , so we choose the negative value.

$\Rightarrow \sin\theta=-\frac{\sqrt{6}}{3}$

The correct answer is B

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3 years ago

What is 1 3/4 gallons, in quarts?

Serggg [28]

Answer: 7 Courts

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3 years ago

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