Question Identify a necessary and sufficient condition for two complex numbers a, b to have a real sum and a real product
Either both numbers are conjugated or both numbers are real numbers. What are complex numbers? Complex numbers are made up of two parts: a real number and an imaginary number. Complex numbers serve as the foundation for more complex math, such as algebra. Consider two complex numbers q and p such that,q=c+id and p=a+ib. A.T.Q. PQ is real and p + q real. pq=(ac−bd)+(bc+ad)i Since PQ is real, the imaginary part must be zero, hence bc+ad=0 or: bc=−ad Then, p+q=(a+c)+(b+d)i Here also b+d must be zero or: d=−b So putting d=−b in bc=−ad, we will get, b(c−a)=0 So either, b=d=0 or, a=c,b=−d So either p and q are conjugated p=a+bi,q=a−bi or both are real p=a,q=c Therefore, either both numbers are conjugated or both numbers are real numbers. Know more about complex numbers here: https://brainly.com/question/16835201 #SPJ4 The correct question is given below: If the product and the sum of two complex numbers are real, what can we say about the numbers? Prove it. Reply
What are complex numbers?