All categories

3 years ago

If i = V-1, then (3 – i)(3+ i) =

Mathematics

1 answer:

castortr0y [4]3 years ago

4 0

9-i^2
9-v^+2v-1
-v^2 +2v +8

You might be interested in

Now given a rope hanging from the top of a pole. The end lying on the ground is 3 chi long. When tightly stretchedit is 8 chi fr

drek231 [11]

Answer:

Height of the pole = 9.17 chi.

Length of the rope = 12.17 chi.

Step-by-step explanation:

Given that the rope is hanging from the top of a pole having height x chi and the portion of the rope lying on the ground is 3 chi.

So, the length of the rope= x + 3 chi.

Let AB represents the pole in the figure, and one end of the rope is at point A.

When the rope is tightly stretched, let C be the other end of the rope as shown in the triangle.

The length of the rope = AC.

\Rightarrow AC=x+3 chi.

Distance from the bottom of the pole, point A, to the other end of the pole, point B, is 8 chi.

So, BC=8 chi.

As the triangle ABC is a right-angled triangle, so by using Pythagoras theorem,

$AC^2= AB^2+BC^2$

$\Rightarrow (x+3)^2=x^2+8^2$

$\Rightarrow x^2+6x+9=x^2+64$

$\Rightarrow 6x=64-9=55$

$\Rightarrow x=55/6=9.17$ chi.

Hence, the height of the pole, $AB=x=9.17$ chi,

and the length of the rope, $x+3=9.17+3=12.17$ chi.

8 0

3 years ago

In the following picture, (QS) ̅ and (PR) ̅ are chords of the circle. Find the length of QS. (Remember to show formulas/equation

Inessa [10]

<h3>Answer: QS is 37 units long</h3>

=========================================

Explanation:

PN = 24 and NR = 14 are pieces of the chord PR. The two pieces multiply to some value. At the same time, the other two pieces QN = 21 and NS = 2x-4 also multiply to that same value. In short, the chord pieces multiply to the same number. This is known as the intersecting chord theorem.

PN*NR = QN*NS

24*14 = 21*(2x-4)

336 = 42x-84

336+84 = 42x-84+84 .... add 84 to both sides

420 = 42x

42x = 420

42x/42 = 420/42 ...... divide both sides by 42

x = 10

We know that x = 10 so we can use it to find the length of NS

NS = 2x-4

NS = 2*10-4

NS = 20-4

NS = 16

Therefore,

QS = QN + NS

QS = 21 + 16

QS = 37

--------

note: as a check,

PN*NR = QN*NS

24*14 = 21*16

336 = 336

we get a true equation, so we have the proper values

4 0

3 years ago

If you reflect triangle MOV across the x-axis, what is the coordinate of O in the image?

Zina [86]

Hi,

The answer you are looking for is 2. (-4,2)

Have a great day & remember to mark brainliest if I helped :)

4 0

3 years ago

Read 2 more answers

Can someone please answer. There is one problem. There's a picture. Thank you!

julia-pushkina [17]

$A=\pi\cdot (2.5)^2=6.25\pi\approx19.63$

7 0

3 years ago

Read 2 more answers

How many times dose 21 go i, to 39?

Andrew [12]

If you want the answer youse a calculator or do 21 divided by 38

5 0

3 years ago