I am doing a math project where I am modeling a shape using a piecewise function. I am then using an online calculator to carry out double integration. However for the equation:
r = 5cos(2θ)-1, 2.85 ≤ r ≤ 4
I keep on getting a negative volume (see picture). I have also plotted the region I am trying to find the of volume on Desmos, if that's helpful (see picture 2). I really have no idea what to do and my math teacher could not offer any help.
