Answer:
19
Step-by-step explanation:
qwertyuiop[sdfghjkl;zxcvbnm,.
where C is the circumference, d is the diameter and r is the radius.
The diameter of a circle is a line segment that passes through the center of the circle and has its endpoints on the circle. The radius of the circle is a line segment from the center of the circle to a point on the circle. The diameter of a circle is twice the length of its radius.
If you are given the diameter then use the formula C = πd
If you are given the radius then use the formula C = 2πr
Step-by-step explanation:
Why is there a question mark?
Answer:
option B
![\frac{31}{50}-\frac{4}{25} i](https://tex.z-dn.net/?f=%5Cfrac%7B31%7D%7B50%7D-%5Cfrac%7B4%7D%7B25%7D%20i)
Step-by-step explanation:
Given in the question a complex fraction
<h3>Step1</h3>
To divide complex numbers, you must multiply by the conjugate. To find the conjugate of a complex number all you have to do is change the sign between the two terms in the denominator.
![\frac{5+4i}{6+8i}(\frac{6-8i}{6-8i})](https://tex.z-dn.net/?f=%5Cfrac%7B5%2B4i%7D%7B6%2B8i%7D%28%5Cfrac%7B6-8i%7D%7B6-8i%7D%29)
<h3>Step2</h3>
Distribute (or FOIL) in both the numerator and denominator to remove the parenthesis.
![\frac{30+24i-40i-32i²}{36-64i^{2} }](https://tex.z-dn.net/?f=%5Cfrac%7B30%2B24i-40i-32i%C2%B2%7D%7B36-64i%5E%7B2%7D%20%7D)
<h3>Step3</h3>
Simplify the powers of i, specifically remember that i² = –1.
![\frac{62-16i}{36+64}](https://tex.z-dn.net/?f=%5Cfrac%7B62-16i%7D%7B36%2B64%7D)
<h3>Step4</h3>
![\frac{62}{100}-\frac{16i}{100}](https://tex.z-dn.net/?f=%5Cfrac%7B62%7D%7B100%7D-%5Cfrac%7B16i%7D%7B100%7D)
<h3>Step5</h3>
simply
![\frac{31}{50}-\frac{4}{25}i](https://tex.z-dn.net/?f=%5Cfrac%7B31%7D%7B50%7D-%5Cfrac%7B4%7D%7B25%7Di)