Question

which trig function is this? tan sin cos

Explanation:

Step1: Recall trigonometric function definitions

In a right - triangle, $\tan\theta=\frac{\text{opposite}}{\text{adjacent}}$, $\sin\theta=\frac{\text{opposite}}{\text{hypotenuse}}$, $\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}$.
For the given angle $\theta$, the side opposite to $\theta$ is $8$ and the side adjacent to $\theta$ is $18$.

Step2: Match with function formula

Since we have the ratio of the opposite side ($8$) and the adjacent side ($18$), and $\tan\theta=\frac{\text{opposite}}{\text{adjacent}}$.

Answer:

$\tan$