Is tan theta positive or negative in this case? ![enter image description here]( Is the value of tangent of an anti-clockwise angle as seen in the image positive or negative if it is in 4th quadrant? I know that tangent of a positive angle is positive value but I have learned that in 4th quadrant tan is negative. So where iam going wrong?

Draw a perpendicular from the pointed end of the arrow to the positive direction of $x$ axis.Now,by definition of $\tan\theta=\frac{opposite\space side}{adjacent\space side}$ we find that $opposite\space side$ is negative as it is in the negative direction of $y-axis$.hence $\tan\theta$ is negative.

![enter image description here](

As the violet part is negative,$\tan\theta$ is negative.