Question

find the value of sin30 - cot 45​

Answer 1

$\LARGE{\rm{\underline{\underline{Answer:-}}}}$

sin 30° - cot 45°

= $\dfrac{1}{2}$ - 1

= $\dfrac{1 - 1\times 2}{2}$

= $\dfrac{1 - 2}{2}$

= $\dfrac{-1}{2}$

Or

= - 0.5

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▪︎ Trigonometric Table:-

$\Large{ \begin{tabular}{|c|c|c|c|c|c|} \cline{1-6} \theta & \sf 0^{\circ} & \sf 30^{\circ} & \sf 45^{\circ} & \sf 60^{\circ} & \sf 90^{\circ} \\ \cline{1-6} \sin & 0 & \dfrac{1}{2 } & \dfrac{1}{ \sqrt{2} } & \dfrac{ \sqrt{3}}{2} & 1 \\ \cline{1-6} \cos & 1 & \dfrac{ \sqrt{ 3 }}{2} } & \dfrac{1}{ \sqrt{2} } & \dfrac{ 1 }{ 2 } & 0 \\ \cline{1-6} \tan & 0 & \dfrac{1}{ \sqrt{3} } & 1 & \sqrt{3} & \infty \\ \cline{1-6} \cot & \infty & \sqrt{3} & 1 & \dfrac{1}{ \sqrt{3} } &0 \\ \cline{1 - 6} \sec & 1 & \dfrac{2}{ \sqrt{3}} & \sqrt{2} & 2 & \infty \\ \cline{1-6} \csc & \infty & 2 & \sqrt{2 } & \dfrac{ 2 }{ \sqrt{ 3 } } & 1 \\ \cline{1 - 6}\end{tabular}}$

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Answer 2

Answer:

sin 30° - cot 45°

= \dfrac{1}{2}21 - 1

= \dfrac{1 - 1\times 2}{2}21−1×2

= \dfrac{1 - 2}{2}21−2

= \dfrac{-1}{2}2−1

Or

= - 0.5