### Instruction: In polar coordinates, the point $\left( -2, \frac{3 \pi}{8} \right)$ is equivalent to what other point, in the standard polar coordinate representation?  Enter your answer in the form $(r,\theta),$ where $r > 0$ and $0 \le \theta < 2 \pi.$.### Response: I recall that polar coordinates use the distance from the origin and the angle from the positive x-axis to describe a point in the plane.
The given point has a negative distance, which means it is in the opposite direction from the angle.
To find the equivalent point with a positive distance, I need to add $\pi$ to the angle and take the absolute value of the distance.
So, the equivalent point is $\left( 2, \frac{11 \pi}{8} \right)$.