JEE Advanced2008MathematicsComplex NumberActual
A particle P starts from the point z₀=1+2 i , where i= -1 . It moves first horizontally away from origin by 5 units and then vertically away from origin by 3 units to reach a point z₁ . From z₁ the particle moves 2 units in the direction of the vector i + j and then it moves through an angle 2 in anti-clockwise direction on a circle with centre at origin, to reach a point z₂ . The point z₂ is given by
Options
- A6+7 i
- B-7+6 i
- C7+6 i
- D-6+7 i
Correct answer
D. -6+7 i
Step-by-step solution
z₂^ = (6+ 2 45^ , 5+ 2 45^ )=(7,6)=7+6 i By rotation about (0,0) , aligned & z₂ z₂^ =e^ i 2 & z₂=z₂^ (e^ i 2 ) & z₂=(7+6 i) ( - +i - )=(7+6 i)(i)=-6+7 i aligned