دانلود اپلیکیشن
نسبت های مثلثاتی زاویه °135 را به دو روش به دست آورید.
روش اول:
\(\begin{array}{l}\sin {135^ \circ } = \sin \left( {{{180}^ \circ } - {{45}^ \circ }} \right) = \sin {45^ \circ } = \frac{{\sqrt 2 }}{2}\\\cos {135^ \circ } = \cos \left( {{{180}^ \circ } - {{45}^ \circ }} \right) = - \cos {45^ \circ } = - \frac{{\sqrt 2 }}{2}\\\tan {135^ \circ } = \tan \left( {{{180}^ \circ } - {{45}^ \circ }} \right) = - \tan {45^ \circ } = - 1\\\cot {135^ \circ } = \cot \left( {{{180}^ \circ } - {{45}^ \circ }} \right) = - \cot {45^ \circ } = - 1\end{array}\)
روش دوم:
\(\begin{array}{l}\sin {135^ \circ } = \sin \left( {{{90}^ \circ } + {{45}^ \circ }} \right) = \cos {45^ \circ } = \frac{{\sqrt 2 }}{2}\\\cos {135^ \circ } = \cos \left( {{{90}^ \circ } + {{45}^ \circ }} \right) = - \sin {45^ \circ } = - \frac{{\sqrt 2 }}{2}\\\tan {135^ \circ } = \tan \left( {{{90}^ \circ } + {{45}^ \circ }} \right) = - \cot {45^ \circ } = - 1\\\cot {135^ \circ } = \cot \left( {{{90}^ \circ } + {{45}^ \circ }} \right) = - \tan {45^ \circ } = - 1\end{array}\)
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