Which graph shows the polar coordinates (−3,−π4) plotted?

The graph located in the lower right section represents the point with coordinates (r, θ) = (-3, -π/4).
A point in polar form is described by its magnitude and angle in standard position. When magnitude is negative it means that its angle is +π radians than its equivalent with positive magnitude.
Then, we can determine the angle of the resultant point by means of the following expression:
θ⁻ = θ⁺ + π (1)
Where:
If we know that θ⁺ = -π/4 and r = 3, then the angle of the point in standard position is:
θ⁻ = θ⁺ + π
θ⁻ = -π/4 + π
θ⁻ = 3 · π/4
Hence, the graph located in the lower right section represents the point with coordinates (r, θ) = (-3, -π/4). [tex]\blacksquare[/tex]
To learn more on polar coordinates, we kindly invite to check this verified question: https://brainly.com/question/11657509