Question

Sin inverse x+ 2cos inverse x=π/2 then 4x=?

Answer 1

$Sin^{-1}x+2.cos^{-1}x=\frac{\pi}{2}==>>>{(EQ\:01)}\\Put\:cos^{-1}x=t\\x=cos\:t\\t=cos^{-1}x</p><p>\\</p><p>x=Sin\:\left(\frac{\pi}{2}-t\right)</p><p>\\</p><p>\left(\frac{\pi}{2}-t\right)=Sin^{-1}x</p><p>\\</p><p>\left(\frac{\pi}{2}-t\right)+2t=\frac{\pi}{2}</p><p>\\</p><p>t=0</p><p>\\</p><p>x=cos\:t</p><p>\\</p><p>x=Cos\:0</p><p>\\</p><p>x=1</p><p>\\</p><p>\bold{Then\:4x=4(1)=4}$

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