find the exact value or type \undefined\ tan 90° ?

Explanation:

Step1: Recall the tangent formula

$\tan\theta=\frac{\sin\theta}{\cos\theta}$

Step2: Substitute $\theta = 90^{\circ}$

When $\theta = 90^{\circ}$, $\sin90^{\circ}=1$ and $\cos90^{\circ}=0$. So, $\tan90^{\circ}=\frac{1}{0}$.

Answer:

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