Answer:
Step-by-step explanation:
ANSWER
x = ±1 and y = -4.
Either x = +1 or x = -1 will work
EXPLANATION
If -3 + ix²y and x² + y + 4i are complex conjugates, then one of them can be written in the form a + bi and the other in the form a - bi. In other words, between conjugates, the imaginary parts are same in absolute value but different in sign (b and -b). The real parts are the same
For -3 + ix²y
⇒ real part: -3
⇒ imaginary part: x²y
For x² + y + 4i
⇒ real part: x² + y (since x, y are real numbers)
⇒ imaginary part: 4
Therefore, for the two expressions to be conjugates, we must satisfy the two conditions.
Condition 1: Imaginary parts are same in absolute value but different in sign. We can set the imaginary part of -3 + ix²y to be the negative imaginary part of x² + y + 4i so that the
x²y = -4 ... (I)
Condition 2: Real parts are the same
x² + y = -3 ... (II)
We have a system of equations since both conditions must be satisfied
x²y = -4 ... (I)
x² + y = -3 ... (II)
We can rearrange equation (II) so that we have
y = -3 - x² ... (II)
Substituting into equation (I)
x²y = -4 ... (I)
x²(-3 - x²) = -4
-3x² - x⁴ = -4
x⁴ + 3x² - 4 = 0
(x² + 4)(x² - 1) = 0
(x² + 4)(x-1)(x+1) = 0
Therefore, x = ±1.
Leave alone (x² + 4) as it gives no real solutions.
Solve for y:
y = -3 - x² ... (II)
y = -3 - (±1)²
y = -3 - 1
y = -4
So x = ±1 and y = -4. We can confirm this results in conjugates by substituting into the expressions:
-3 + ix²y
= -3 + i(±1)²(-4)
= -3 - 4i
x² + y + 4i
= (±1)² - 4 + 4i
= 1 - 4 + 4i
= -3 + 4i
They result in conjugates
Answer:
C) 15
Step-by-step explanation:
Here we have to use the combination to find the number of possible combinations.
Total number of classmates (n) = 6
We are selecting 2 individuals. So r = 2.
The combination formula nCr = 
Plug in n = 6 and r =2, in the above formula, we get
= 
= 
Simplifying the above factorial, we get
= 15
So the answer is C) 15
A of the yard= L*l=16*14= 224 feet²
A of the fountain= πR²
d=2R
4=2R
R=4:2=2
A of the fountain= 2²π=4 *3,14= 12,56 feet²
A of the grass portion= 224-12,56= 211,43 feet²
answer d)211,43 feet²
Answer:
Step-by-step explanation:
Reduce the expression -4^2×4^2
Calcualte the product and you get -4^4
If you want the alternative form is will be -256
Hope this helpsʕ•ᴥ•ʔ
