Lunar3lipse
Lunar3lipse Lunar3lipse
  • 02-03-2020
  • Mathematics
contestada

If x+yi/i = 8+ 10i, where x and y are real, what is the value of (x + yi)(x - yi)?
A 164
B 150
C. 75
D. 100

Respuesta :

amna04352
amna04352 amna04352
  • 02-03-2020

Answer:

164

Step-by-step explanation:

(x + iy)/i = 8 + 10i

(x + iy) = (8 + 10i)(i) = 8i + 10i²

= -10 + 8i

(-10 + 8i)(-10 - 8i) = (-10)² + 8² = 164

Answer Link
koyna2001 koyna2001
  • 02-03-2020

Answer:

A.164

Step-by-step explanation:

(x+yi)(x-yi) -> (8+10i)(8-10i)

rule: *(a-b)(a+b)=a^2+b^2

(8+10i)(8-10i) = 64-100i^2

rule: i^2=(-1)

64-100i^2 =  64-100(-1)

=64+100

=164

Answer Link

Otras preguntas

Twice as number decreased by 9 is 7
do you guys what's 5y/3=20
Can some one help me ??? Anyone ?
What does the fact the pi is irrational indicate about it'd decimal equivalent
Last summer, at Camp Okey-Fun-Okey, the radio of the number of boy campers to the number of girl campers was 8:7. If there were a total of 195 campers, how many
How did king james 1 important to the survival of the Jamestown settlers
how do I write 0.25 as a fraction in its simplists form
is 8/5 rational or irrational?
What is the value of 3 in 63.856
What is the rounding or compatible numbers to estimate the sum of 87+34