Solve the equation (z+i)^*=2zi+1.

STEP 1: What the questions asks us is to find z that solves the equation given. Since z is a complex number, we need to determine both its real and imaginary parts. Hence, we begin by writing z in terms of its real and imaginary parts, z = a+bi (notice the imaginary part is whatever is multiplied by the number "i").
STEP 2: Using substitution, this gives (z+i) = a+bi+i. It is also useful to group the real and imaginary parts, in order to get (z+i) = a+(b+1)i.
STEP 3: Express the complex conjugate of (z+i) as (z+i)* = a-(b+1)i.
STEP 4: Substitute everything in original equation, to obtain the following equality: a-(b+1)i = (1-2b)+2ai.
STEP 5: Equate real and imaginary parts to get a system of equations in a and b: a = 1-2b and -(b+1) = 2a
STEP 6: Solve, to obtain a = -1, and b = 1. This gives z = -1+i.

TD

Related Maths A Level answers

All answers ▸

A cup of coffee is cooling down in a room following the equation x = 15 + 70e^(-t/40). Find the rate at which the temperature is decreasing when the coffee cools to 60°C.


The curve C has the equation y=3x/(9+x^2 ) (a) Find the turning points of the curve C (b) Using the fact that (d^2 y)/(dx^2 )=(6x(x^2-27))/(x^2+9)^3 or otherwise, classify the nature of each turning point of C


I already done this.


What is the exact answer to (1^3 + 2^3 + 3^3)^(0.5) ?