Question

which trig function is this? sin tan cos

Explanation:

Step1: Recall trigonometric function definitions

• $\sin\theta=\frac{\text{opposite}}{\text{hypotenuse}}$
• $\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}$
• $\tan\theta=\frac{\text{opposite}}{\text{adjacent}}$

Step2: Identify sides relative to the given angle

For the $20^{\circ}$ angle:

• Adjacent side $= 5$
• Hypotenuse $= 12$

Step3: Match with cosine function

Since $\cos\theta=\frac{\text{adjacent}}{\text{hypotenuse}}$, and we have adjacent $ = 5$ and hypotenuse $= 12$, this is the cosine function.

Answer:

$\cos$