e(∣∣z∣+1∣(∣z∣+3)(∣z∣−1)loge2)≥log2∣57+9i∣
⇒2(∣z∣+1)(∣z∣+3)(∣z∣−1)≥log2(16)
⇒2(∣z∣+1)(∣z∣+3)(∣z∣−1)≥23
(∣z∣+1)(∣z∣+3)(∣z∣−1)≥3
(∣z∣+3)(∣z∣−1)≥3(∣z∣+1)
∣z∣2+2∣z∣−3≥3∣z∣+3
⇒∣z∣2+∣z∣−6≥0
⇒(∣z∣−3)(∣z∣+2)≥0⇒∣z∣−3≥0
⇒∣z∣≥3⇒∣z∣min=3
JEE Main 2021 — Mathematics Algebra
The least value of ∣z∣ where z is complex number which satisfies the inequality e(∣∣z∣+1∣(∣z∣+3)(∣z∣−1)loge2)≥log2∣57+9i∣, i=−1, is equal to :
Held on 16 Mar 2021 · Verified 6 Jul 2026.
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