Precalculus (view picture) pt2

MissTica

Answer:

<u>Secant</u>: a straight line that intersects a circle at two points.

<u>Intersecting Secants Theorem</u>

If two secant segments are drawn to the circle from one exterior point, the product of the measures of one secant segment and its external part is equal to the product of the measures of the other secant segment and its external part.

From inspection of the given diagram:

M = Exterior point
MK = secant segment and ML is its external part
MS = secant segment and MN is its external part

Therefore:

⇒ ML · MK = MN · MS

Given:

MK = (x + 15) + 6 = x + 21
ML = 6
MS = 7 + 11 = 18
MN = 7

Substituting the given values into the formula and solving for x:

⇒ ML · MK = MN · MS

⇒ 6(x + 21) = 7 · 18

⇒ 6x + 126 = 126

⇒ 6x = 0

⇒ x = 0

Substituting the found value of x into the expression for KL:

⇒ KL = x + 15

⇒ KL = 0 + 15

⇒ KL = 15

6 0

2 years ago

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Find the indicated nth partial sum of the arithmetic sequence.<br> −7, −3, 1, 5, . . ., n = 30

TiliK225 [7]

Step-by-step explanation:

Given the Arithmetic sequence

$-7, -3, 1, 5, . . .$

An arithmetic sequence has a constant difference d and is defined by

$a_n=a_1+\left(n-1\right)d$

$\mathrm{Compute\:the\:differences\:of\:all\:the\:adjacent\:terms}:\quad \:d=a_{n+1}-a_n$

$-3-\left(-7\right)=4,\:\quad \:1-\left(-3\right)=4$

$\mathrm{The\:difference\:between\:all\:of\:the\:adjacent\:terms\:is\:the\:same\:and\:equal\:to}$

$d=4$

$\mathrm{The\:first\:element\:of\:the\:sequence\:is}$

$a_1=-7$

as

$a_n=a_1+\left(n-1\right)d$

$\mathrm{Therefore,\:the\:}n\mathrm{th\:term\:is\:computed\:by}\:$

$a_n=4\left(n-1\right)-7$ ∵ $d=4$

$\mathrm{Arithmetic\:sequence\:sum\:formula:}$

$n\left(a_1+\frac{d\left(n-1\right)}{2}\right)$

$\mathrm{Plug\:in\:the\:values:}$

$n=30,\:\space a_1=-7,\:\spaced=4$

$=30\left(-7+\frac{4\left(30-1\right)}{2}\right)$

$=30\left(58-7\right)$ ∵ $\frac{4\left(30-1\right)}{2}=58$

$=30\cdot \:51$

$=1530$ ∵ $\mathrm{Multiply\:the\:numbers:}\:30\cdot \:51=1530$

Therefore, the indicated nth partial sum of the arithmetic sequence is 1530.

ANOTHER METHOD

as

$a_n=4\left(n-1\right)-7$

n = 30

$\sum _{n=1}^{30}\:4\left(n-1\right)-7$

$=\sum _{n=1}^{30}4n-11$

$\mathrm{Apply\:the\:Sum\:Rule}:\quad \sum a_n+b_n=\sum a_n+\sum b_n$

$=\sum _{n=1}^{30}4n-\sum _{n=1}^{30}11$

as

$\sum _{n=1}^{30}4n=1860$

and

$\sum _{n=1}^{30}11=330$

so

$=1860-330$

$=1530$

7 0

4 years ago

Joyce can type 60 words in five minutes. Robert can type 48 words in six minutes words who type at the faster and how many words

erik [133]

Answer:

joyce

Step-by-step explanation:

60/5 =12

48/6 =8

6 0

3 years ago

Which table shows a proportional relationship? Right answer gets brainliest. 100 pts*

Stels [109]

Answer: the second one

Step-by-step explanation:

8 0

3 years ago

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Can someone please answer this, ill give you brainliest Would be very appreciated.

Lorico [155]

Answer:

Given function:

f(t) = (-16t - 2)(t - 1)

The zeros of the function are the values of t when f(t) = 0

⇒ f(t) = 0

⇒ (-16t - 2)(t - 1) = 0

⇒ (t - 1) = 0 ⇒ t = 1

⇒ (-16t - 2) = 0 ⇒ t = -2/16 = -1/8

The zeroes tell us the time (in seconds) when the ball is at ground level (when its height is zero).

Since time is not negative, only one zero is meaningful: t = 1

Therefore, the total journey of the ball, from throwing it to it hitting the ground, is 1 second.

The height the ball is thrown can be determined by inputting t = 0 into the function:

⇒ f(0) = (-16(0) - 2)(0 - 1)

⇒ f(0) = (0 - 2)(0 - 1)

⇒ f(0) = (-2)(-1)

⇒ f(0) = 2

Therefore, the height from which the beach ball is thrown is 2 ft.

4 0

2 years ago

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