Verified Solution • 2025–26 Session moderate

QJEEM19Mad25b: JEE Main 2019 Mathematics - Class 11 JEEM19Mad25b Solution: All the pairs (x, y) that satisfy the inequality also satisfy…

All the pairs (x, y) that satisfy the inequality
2sin⁡2x−2sin⁡x+5.14sin⁡2y≤1{2^{\sqrt {{{\sin }^2}x - 2\sin x + 5} }}.{1 \over {{4^{{{\sin }^2}y}}}} \le 1
also satisfy the equation

Multiple Choice Options

  • A sin x = |sin y|
  • B sin x = 2sin y
  • C 2 sin x = sin y
  • D 2 |sin x | = 3 sin y

Step-by-Step Verified Solution

2sin⁡2x−2sin⁡x+5≤22sin⁡2y{2^{\sqrt {{{\sin }^2}x - 2\sin x + 5} }} \le {2^{2{{\sin }^2}y}}

⇒\Rightarrow sin⁡2x−2sin⁡x+5≤2sin⁡2y\sqrt {{{\sin }^2}x - 2\sin x + 5} \le 2{\sin ^2}y

⇒(sin⁡x−1)2+4≤2sin⁡2y\Rightarrow \sqrt {{{\left( {\sin x - 1} \right)}^2} + 4} \le 2{\sin ^2}y

it is true when sinx = 1, |siny| = 1

so sinx = |siny|

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