Which formula gives the x-coordinates of the maximum values for y = cos(x)?

Aplot of land in the shape of a vertical ellipse has a pole at each focus. the foci are 8 feet from the center. if the plot of land is 34 feet across the vertical axis, then it is (a.24 b. 30 c. 32 d. 36) feet across the other axis. the eccentricity of the ellipse traced by the boundary of this plot, rounded to the nearest thousandth, is (a.0.543 b.0.515 c.0.471 d. 0.459)