If $x\mathit{=}\mathit{Tan}\mathit{15}\mathit{°}\mathit{,}y\mathit{=}\mathit{ }\mathit{Cosec}\mathit{75}\mathit{°}$ and  $Z\mathit{=}\mathit{4}\mathit{Sin}\mathit{18}\mathit{°}$ then

$x\mathit{=}tan\mathit{15}$

$x\mathit{=}\mathit{2}\mathit{-}\sqrt{\mathit{3}}\mathit{=}\mathit{2}\mathit{-}\mathit{1}\mathit{.}\mathit{73}$

= 0.27

$y\mathit{=}\mathit{cosec}\mathit{75}$

$=\frac{2\sqrt{2}}{\sqrt{3}+1}=2\sqrt{2}\frac{(\sqrt{3}-1)}{2}$

$=\sqrt{6}-\sqrt{2}$

$=2.44-1.41$

$=1.03$

$z=4·\sin 18$

$=4·\frac{\sqrt{5}-1}{4}=2.23-1$

$=1.23$

$x<y<z$