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:
75,361,700
Step-by-step explanation:
find the hundredths place, if the number to the right is higher than or equal to 5 increase the number in the hundredth place by 1, if not keep the number the same (so 6 will turn into 7) and make the numbers after that 0s. Copy down the numbers exactly like they are but with the rounded hundredth place.
Answer:
(10,8)
Step-by-step explanation:
Symmetry over x axis: you keep x, but change the sign of y value.
So, the symmetric of (10,-8) is (10,8)
Answer:
7/3
Step-by-step explanation:
i hope this works :)
Answer:
Type I error
Step-by-step explanation:
A type I error occurs if the null hypothesis is rejected when it is actually true.
Type I Type II
Reject null when true Fail to reject null when not true
Null hypothesis: ∪ = 30%
Alternative hypothesis: ∪ > 30%
The researchers concluded that more than 30% of first-grade students at this school have entered the concrete operational stage of development and they rejected the null hypothesis.
However, a census actually found that in the population of all first graders at this school, only 28% have entered the concrete operational stage.
A type I error has been made because in actuality the null hypothesis was true but was rejected.
