Test your skills with complex numbers by solving an intriguing equation involving square roots. This quiz is perfect for students and enthusiasts of advanced algebra.
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Question 1
What is a common first step when solving the equation √k + √-k = 15 in the complex plane?
A.Assume k is a real number.
B.Let √k = z.
C.Square both sides immediately.
D.Substitute k = x + yi.
Question 2
If √k = z, what is √-k in terms of z, assuming principal roots and that √(-1) = i?
A.z/i
B.-z
C.iz
D.-iz
Question 3
After substituting √k = z and √-k = iz, what is the resulting linear equation for z?
A.z^2 - z = 15i
B.z + iz = 15
C.z - iz = 15
D.z^2 + (iz)^2 = 15
Question 4
From the equation z(1 + i) = 15, what is the first step to isolate z?
A.Subtract i from both sides.
B.Divide both sides by (1 + i).
C.Multiply by (1 - i).
D.Divide both sides by 15.
Question 5
To simplify z = 15 / (1 + i), which expression should you multiply the numerator and denominator by?
A.(1 + i)
B.i
C.(1 - i)
D.-i
Question 6
What is the value of z in the equation z = 15 / (1 + i)?
A.-7.5 - 7.5i
B.7.5 + 7.5i
C.15 - 15i
D.7.5 - 7.5i
Question 7
If z = √k, and you've found z, how do you calculate k?
A.k = z
B.k = √z
C.k = z^2
D.k = 1/z
Question 8
If z = a + bi, what is z^2?
A.a^2 + b^2
B.a^2 - b^2 + 2abi
C.a^2 - b^2
D.a^2 + b^2 - 2abi
Question 9
Given z = 7.5 - 7.5i, what is the value of k = z^2?
A.-112.5i
B.112.5
C.112.5i
D.-112.5
Question 10
If the problem specified that 'k' must be a real number, how many solutions would there be for √k + √-k = 15?