Answer:
Attachment 1 : Option C
Attachment 2 : Option A
Step-by-step explanation:
( 1 ) Expressing the product of z1 and z2 would be as follows,
![14\left[\cos \left(\frac{\pi \:}{5}\right)+i\sin \left(\frac{\pi \:\:}{5}\right)\right]\cdot \:2\sqrt{2}\left[\cos \left(\frac{3\pi \:}{2}\right)+i\sin \left(\frac{3\pi \:\:}{2}\right)\right]](https://tex.z-dn.net/?f=14%5Cleft%5B%5Ccos%20%5Cleft%28%5Cfrac%7B%5Cpi%20%5C%3A%7D%7B5%7D%5Cright%29%2Bi%5Csin%20%5Cleft%28%5Cfrac%7B%5Cpi%20%5C%3A%5C%3A%7D%7B5%7D%5Cright%29%5Cright%5D%5Ccdot%20%5C%3A2%5Csqrt%7B2%7D%5Cleft%5B%5Ccos%20%5Cleft%28%5Cfrac%7B3%5Cpi%20%5C%3A%7D%7B2%7D%5Cright%29%2Bi%5Csin%20%5Cleft%28%5Cfrac%7B3%5Cpi%20%5C%3A%5C%3A%7D%7B2%7D%5Cright%29%5Cright%5D)
Now to solve such problems, you will need to know what cos(π / 5) is, sin(π / 5) etc. If you don't know their exact value, I would recommend you use a calculator,
cos(π / 5) = 
,
sin(π / 5) = 
cos(3π / 2) = 0,
sin(3π / 2) = - 1
Let's substitute those values in our expression,
![14\left[\frac{\sqrt{5}+1}{4}+i\frac{\sqrt{2}\sqrt{5-\sqrt{5}}}{4}\right]\cdot \:2\sqrt{2}\left[0-i\right]](https://tex.z-dn.net/?f=14%5Cleft%5B%5Cfrac%7B%5Csqrt%7B5%7D%2B1%7D%7B4%7D%2Bi%5Cfrac%7B%5Csqrt%7B2%7D%5Csqrt%7B5-%5Csqrt%7B5%7D%7D%7D%7B4%7D%5Cright%5D%5Ccdot%20%5C%3A2%5Csqrt%7B2%7D%5Cleft%5B0-i%5Cright%5D)
And now simplify the expression,
The exact value of 
= 
and 
= 
Therefore we have the expression 
, which is close to option c. As you can see they approximated the solution.
( 2 ) Here we will apply the following trivial identities,
cos(π / 3) = 
,
sin(π / 3) = 
,
cos(- π / 6) = ,
sin(- π / 6) = 
Substitute into the following expression, representing the quotient of the given values of z1 and z2,
![15\left[cos\left(\frac{\pi \:}{3}\right)+isin\left(\frac{\pi \:\:}{3}\right)\right] \div \:3\sqrt{2}\left[cos\left(\frac{-\pi \:}{6}\right)+isin\left(\frac{-\pi \:\:}{6}\right)\right]](https://tex.z-dn.net/?f=15%5Cleft%5Bcos%5Cleft%28%5Cfrac%7B%5Cpi%20%5C%3A%7D%7B3%7D%5Cright%29%2Bisin%5Cleft%28%5Cfrac%7B%5Cpi%20%5C%3A%5C%3A%7D%7B3%7D%5Cright%29%5Cright%5D%20%5Cdiv%20%5C%3A3%5Csqrt%7B2%7D%5Cleft%5Bcos%5Cleft%28%5Cfrac%7B-%5Cpi%20%5C%3A%7D%7B6%7D%5Cright%29%2Bisin%5Cleft%28%5Cfrac%7B-%5Cpi%20%5C%3A%5C%3A%7D%7B6%7D%5Cright%29%5Cright%5D)
⇒
![15\left[\frac{1}{2}+\frac{\sqrt{3}}{2}\right]\div \:3\sqrt{2}\left[\frac{\sqrt{3}}{2}+-\frac{1}{2}\right]](https://tex.z-dn.net/?f=15%5Cleft%5B%5Cfrac%7B1%7D%7B2%7D%2B%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7D%5Cright%5D%5Cdiv%20%20%5C%3A3%5Csqrt%7B2%7D%5Cleft%5B%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7D%2B-%5Cfrac%7B1%7D%7B2%7D%5Cright%5D)
The simplified expression will be the following,
or in other words 
or 
The solution will be option a, as you can see.
Answer:
30 =z
Step-by-step explanation:
-15 = z/-2
Multiply each side by -2 to isolate z
-2 * -15 = z/ -2 * -2
30 =z
Answer:
<h3>The option B) is correct</h3><h3>Therefore the coordinate of B
is (6,-3)</h3>
Step-by-step explanation:
Given that the midpoint of segment AB is (4, 2). The coordinates of point A is (2, 7).
<h3>To Find the coordinates of point B:</h3>
- Let the coordinate of A be
is (2,7) respectively - Let the coordinate of B be
- And Let M(x,y) be the mid point of line segment AB is (4,2) respectively
- The mid-point formula is
<h3>
</h3>
- Now substitute the coordinates int he above formula we get
- Now equating we get
Multiply by 2 we get Multiply by 2 we get
Subtracting 2 on both
the sides Subtracting 7 on both the sides
Rewritting the above equation Rewritting the equation
<h3>Therefore the coordinate of B
is (6,-3)</h3><h3>Therefore the option B) is correct.</h3>
