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3 years ago

Find the value of x A.25 B.85 C.75 D.105

Mathematics

1 answer:

Masteriza [31]3 years ago

7 0

Answer:

The value of x is 75

Step-by-step explanation:

First we need to find the other angle that doesn't have a number in it.

To find the degrees of the other angle we subtract 155 from 180.

180 - 155 = 25

Now we have to find the value of x. Add 80 and 25 together to get 105. A triangle is going to be 180 degrees. Subtract 105 from 180.

180 - 105 = 75

Now we will add 80, 25, and 75 to check our work.

80+25+75 = 180

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Please help will give brainlist!

Yuki888 [10]

Answer:

$b=\frac{1}{6}$

Step-by-step explanation:

In $f(x)=a\cos(b(x-c))+d$ , $b$ represents a constant related to the period of the function. Here's how it's related:

$b=\frac{2\pi}{T}$ , where $T$ is the period of the function.

We're given $T=12\pi$ , so solving for $b$ :

$b=\frac{2\pi}{12\pi}=\boxed{\frac{1}{6}}$

4 0

2 years ago

What is Permutations and Combinations?

marissa [1.9K]

Answer:

See below

Step-by-step explanation:

Permutation is to select an object then arrange it and it cares about the orders while Combination is about only selecting an object without caring the orders.

Permutation can be expressed in math as:

$\displaystyle{_n P _r = \dfrac{n!}{(n-r)!} \ \ \ (n \geq r) }$

where n is a number of total object and r is a number of selected object to arrange. Hence. n cannot be less than r.

Now let's see an example of permutation, suppose we have letter A, B and C. I'd like to know how many ways these words can be arranged:

Since there are 3 letters total and 3 selected letters to arrange then:

$\displaystyle{_3 P _3 = \dfrac{3!}{(3-3)!}}\\\\\displaystyle{_3 P _3 = \dfrac{3 \times 2 \times 1}{0!}}\\\\\displaystyle{_3 P _3 = \dfrac{6}{1}}\\\\\displaystyle{_3 P _3 = 6}$

Therefore, there are 6 ways to arrange the letters - we can also demonstrate visually:

ABC - 1

ACB - 2

BAC - 3

BCA - 4

CAB - 5

CBA - 6

Notice that if you do visually, you'll get the same answer as the calculation of permutation!

----

Combination can be expressed mathematically as:

$\displaystyle{_n C _r = \dfrac{n!}{(n-r)!r!} = \dfrac{_n P _r}{r!} \ \ \ (n \geq r) }$

The difference between permutation and combination is that you only find how many ways you can select object in combination. Therefore, no arrange and doesn't care about order, just ways to select.

Suppose we have same 3 letters: A, B and C. I want to find how many ways I can select these 3 letters:

Since there are 3 letters total and 3 selected letters:

$\displaystyle{_3 C _3 = \dfrac{3!}{(3-3)!3!}}\\\\\displaystyle{_3 C _3 = \dfrac{3!}{0!3!}}\\\\\displaystyle{_3 C _3 = \dfrac{3!}{3!}}\\\\\displaystyle{_3 C _3 = 1}$