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QJEEM21Ma949c: JEE Main 2021 Mathematics - Class 11 JEEM21Ma949c Solution: If the real part of the complex number is zero, then the value…

If the real part of the complex number z=3+2icos⁡θ1−3icos⁡θ,θ∈(0,π2)z = {{3 + 2i\cos \theta } \over {1 - 3i\cos \theta }},\theta \in \left( {0,{\pi \over 2}} \right) is zero, then the value of sin23 θ\theta + cos2 θ\theta is equal to _______________.

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Re (z)=3−6cos⁡2θ1+9cos⁡2θ=0(z) = {{3 - 6{{\cos }^2}\theta } \over {1 + 9{{\cos }^2}\theta }} = 0

⇒\Rightarrow θ\theta = π4{{\pi \over 4}}

Hence, sin23 θ\theta + cos2 θ\theta = 1.

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