## Algebra 2 (1st Edition)

$\sin 90^{\circ}=1$ $\cos 90^{\circ}=0$ $\tan 90^{\circ}=\infty$ (undefined) $\csc 90^{\circ}= 1$ $\sec 90^{\circ}=\infty$ (undefined) $\cot 90^{\circ}=0$
When $\dfrac{\pi}{2}=\dfrac{\pi}{2} \times \dfrac{180}{\pi}=90^{\circ}$ The Trigonometric Identities can be defined as: $\sin 90^{\circ}=1$ $\cos 90^{\circ}=0$ $\tan 90^{\circ}=\infty$ (undefined) $\csc 90^{\circ}= 1$ $\sec 90^{\circ}=\infty$ (undefined) $\cot 90^{\circ}=0$