Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE MainMathematicsComplex Number

Let S be the set of all non-real complex numbers z satisfying z^4 = z (|z|^2 - 3|z| + 3) . Then the value of _ z S (3 - z) is equal to _____ .

Correct answer

121

Step-by-step solution

Given the equation z^4 = z (|z|^2 - 3|z| + 3) . Taking the modulus on both sides: |z^4| = | z | | |z|^2 - 3|z| + 3 | Since |z|^2 - 3|z| + 3 = (|z| - 3 2 )^2 + 3 4 > 0 , we can drop the absolute value on the real quadratic: |z|^4 = |z| (|z|^2 - 3|z| + 3) Since z is non-real, z 0 , so we can divide by |z| : |z|^3 = |z|^2 - 3|z| + 3 |z|^3 - |z|^2 + 3|z| - 3 = 0 Factoring by grouping: |z|^2(|z| - 1) + 3(|z| - 1) = 0 (|z| - 1)(|z|^2 + 3) = 0 Since |z| is a real number, |z|^2 + 3 0 . Thus, |z| = 1 . Substitute |z| = 1 ba

Practice Complex Number on Quantrex Academy →

More from Complex Number

The number of values of z C , satisfying the equations |z-(4+8i)|= 10 and |z-(3+5i)|+|z-(5+11i)|=4 5 , is: 2026Let S = z C : z^2 + 6 ,iz - 3 = 0 . Then _ z S z^8 is equal to : 2026Let the set of all values of k R such that the equation z( z + 2 + i) + k(2 + 3i) = 0 , z C , has at least one solution, be the interval [ , ] . Then 9( + ) is equal to: 2026Let z₁, z₂ C be the distinct solutions of the equation z^2 + 4z - (1 + 12i) = 0 . Then |z₁|^2 + |z₂|^2 is equal to : 2026Let S= z C : z^2+4z+16=0 . Then _ z S |z+ 3 i|^2 is equal to: 2026Let z be a complex number such that |z+2| = |z-2| and ( z+3 z-i ) = 4 . Then |z|^2 is equal to: 2026Let the circles C₁ : |z| = r and C₂ : |z - 3 - 4i| = 5 , z C , be such that C₂ lies within C₁ . If z₁ moves on C₁ , z₂ moves on C₂ and |z₁ - z₂| = 2 , then |z₁ - z₂| is equal to: 2026Let x and y be real numbers such that 50 ( 2x 1+3i - y 1-2i ) = 31 + 17i , i = -1 . Then the value of 10(x - 3y) is : 2026 Full Complex Number list All JEE Main PYQs