The sum of the interior angles of a 14-gon = (14-2)*180 = 2,160 degrees. There are 14 vertexes (vertices) for a 14-gon. It is 'regular' so all these angles are equal. By dividing 2160 (sum of all angles) by 14 (total amount of angles) we can see how much each angle is worth. So the interior angle of each is 154.285 degrees.

4 0

3 years ago

Please help me in this questions....

Ivahew [28]

Part (i)

I'm going to use the notation T(n) instead of $T_n$

To find the first term, we plug in n = 1

T(n) = 2 - 3n

T(1) = 2 - 3(1)

T(1) = -1

The first term is -1

Repeat for n = 2 to find the second term

T(n) = 2 - 3n

T(2) = 2 - 3(2)

T(2) = -4

The second term is -4

<h3>Answers: -1, -4</h3>

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Part (ii)

Plug in T(n) = -61 and solve for n

T(n) = 2 - 3n

-61 = 2 - 3n

-61-2 = -3n

-63 = -3n

-3n = -63

n = -63/(-3)

n = 21

Note that plugging in n = 21 leads to T(21) = -61, similar to how we computed the items back in part (i).

<h3>Answer: 21st term</h3>

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Part (iii)

We're given that T(n) = 2 - 3n

Let's compute T(2n). We do so by replacing every copy of n with 2n like so

T(n) = 2 - 3n

T(2n) = 2 - 3(2n)

T(2n) = 2 - 6n

Now subtract T(2n) from T(n)

T(n) - T(2n) = (2-3n) - (2-6n)

T(n) - T(2n) = 2-3n - 2+6n

T(n) - T(2n) = 3n

Then set this equal to 24 and solve for n

T(n) - T(2n) = 24

3n = 24

n = 24/3

n = 8

This means 2n = 2*8 = 16. So subtracting T(8) - T(16) will get us 24.

<h3>Answer: 8</h3>

4 0

3 years ago

Which expression is equivalent to (cos x)(tan(–x))?

Naya [18.7K]

The tan(-x) is the same thing as -tan(x). The tangent function is also the same thing as sin(x)/cos(x), right? So let's rewrite that tan in terms of sin and cos:
$[cos(x)][tan(-x)]$ is the same as $[cos(x)][ -\frac{sin(x)}{cos(x)}]$
We can now cancel out the cos(x), which leaves us only with -sin(x) remaining. So your answer is A.

7 0

3 years ago

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