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3 years ago

How to do this question

Mathematics

1 answer:

Bas_tet [7]3 years ago

7 0

9514 1404 393

Answer:

AB = [[-6, -1][-4, 6][-15, 10]]

Step-by-step explanation:

Any of a number of on-line, spreadsheet, or calculator tools will find the matrix product for you.

The input and output of one such tool is shown below.

As you know, each term in the product matrix is the sum of products of a row in the left matrix and a column in the right matrix. The coordinates of that row and column are the coordinates of the result in the product matrix.

For example, row 2, column 1 of the product matrix is the sum of products ...

(4)(-3) +(-2)(-4) = -12 +8 = -4 . . . . row 2, column 1 of the result

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A CIRCLE HAS A CIRCUMFENCE 43.96 YD FIND THE RADUIS OF THE CIRCLE

sleet_krkn [62]

Answer:

≈ 7

Step-by-step explanation:

8 0

3 years ago

<img src="https://tex.z-dn.net/?f=9%20%5Cdiv%202.43" id="TexFormula1" title="9 \div 2.43" alt="9 \div 2.43" align="absmiddle" cl

blsea [12.9K]

Is this a question? Nine divided by 2.43 is 3.703703703703703703

3 0

3 years ago

Hello! Verify the identity. Please show your work! Use trigonometric identities to verify each expression is equal.

RSB [31]

Answer:

See Below.

Step-by-step explanation:

We want to verify the identity:

$\displaystyle \csc^2 x -2\csc x \cot x +\cot ^2 x = \tan^2\left(\frac{x}{2}\right)$

Note that the left-hand side is a perfect square trinomial pattern. Namely:

$a^2-2ab+b^2=(a-b)^2$

If we let a = csc(x) and b = cot(x), we can factor it as such:

$\displaystyle (\csc x - \cot x)^2 = \tan^2\left(\frac{x}{2}\right)$

Let csc(x) = 1 / sin(x) and cot(x) = cos(x) / sin(x):

$\displaystyle \left(\frac{1}{\sin x}-\frac{\cos x }{\sin x}\right)^2=\tan^2\left(\frac{x}{2}\right)$

Combine fractions:

$\displaystyle \left(\frac{1-\cos x}{\sin x}\right)^2=\tan^2\left(\frac{x}{2}\right)$

Square (but do not simplify yet):

$\displaystyle \frac{(1-\cos x)^2}{\sin ^2x}=\tan^2\left(\frac{x}{2}\right)$

Now, we can make a substitution. Let u = x / 2. So, x = 2u. Substitute:

$\displaystyle \frac{(1-\cos 2u)^2}{\sin ^22u}=\tan^2u$

Recall that cos(2u) = 1 - sin²(u). Hence:

$\displaystyle \frac{(1-(1-2\sin^2u))^2}{\sin ^2 2u}=\tan^2u$

Simplify:

$\displaystyle \frac{4\sin^4 u}{\sin ^2 2u}=\tan^2 u$

Recall that sin(2u) = 2sin(u)cos(u). Hence:

$\displaystyle \frac{4\sin^4 u}{(2\sin u\cos u)^2}=\tan^2 u$

Square:

$\displaystyle \frac{4\sin^4 u}{4\sin^2 u\cos ^2u}=\tan^2 u$

Cancel:

$\displaystyle \frac{\sin ^2 u}{\cos ^2 u}=\tan ^2 u$

Since sin(u) / cos(u) = tan(u):

$\displaystyle \left(\frac{\sin u}{\cos u}\right)^2=\tan^2u=\tan^2u$

We can substitute u back for x / 2:

$\displaystyle \tan^2\left(\frac{x}{2}\right)= \tan^2\left(\frac{x}{2}\right)$

Hence proven.

3 0

3 years ago

What is the value of the expression 8.3 × 104 − 2.5 × 103 − 1.9 × 104 written in scientific notation?

bezimeni [28]

Remark work with the two numbers that are 10^4 first. Then add in the one that goes to 10^3

Method one
You could change these all to integers and then take it back to scientific notation.

83 000
-19 000
64 000
- 2 500
 61 500 <<<<<< answer

Method two
Keep the scientific notation.
8.3 * 10^4
-1.9 * 10^4
6.4 * 10^4
- .25*10^4 Note the powers of ten must be the same.
6.15*10^4 <<<<<<<< answer

Either method works.

You could use your calculator to get the right answer. I'm not sure all calculators retain the scientific notation. Test yours to see what it does. Enter 8.3*10y^x 4 *1 =

Your calculator might have x^y or ^ to record powers. You may also have EE and one of your keys.

See if your calculator returns 8.3*10^4 or if it returns 83000

4 0

3 years ago

Read 2 more answers

Let f(x) = - 3x-1, h(x) = - X+3. Find (f o h)(-7)

gtnhenbr [62]

Answer:

f(x)= 20 h(x)= -4

Step-by-step explanation:

ive learnd this already :)

8 0

3 years ago