NDA2021MathematicsComplex NumberActual
If z=x+i y , where i= -1 , then what does the equation z z +|z|^2+4(z+ z )-48=0 represent?
Options
- AStraight line
- BParabola
- CCircle
- DPair of straight lines
Correct answer
C. Circle
Step-by-step solution
Here z=x+i y z =x-i y aligned & z z +|z|^2+4(z+ z )-48=0 & |z|^2+|z|^2+4(z+ z )-48=0 [ z z =|z|^2 ] & 2 (x^2+y^2 )+4(2 x)-48=0 & x^2+y^2+4 x-48=0 aligned Represent equation of circles.