Consider the graph of r -y 42 0. What does the cross-section in the ry plane loo
ID: 2884039 • Letter: C
Question
Consider the graph of r -y 42 0. What does the cross-section in the ry plane look like? A. a parabola B. a hyperbola C. an ellipse D. a circle E. empty F. a line or lines G. a point What do the cross-sections parallel to the plane look like? (Some of them may be empty--tell me about the ones that aren't) A. hyperbolas B. circles C. parabolas D. ellipses What does the cross-section in the plane look like? A. a point B. an ellipse C. a hyperbola. D. a line or lines E. a parabola F. empty G. a circle What do the cross-sections parallel to the plane look like? (Some of them may be empty--tell me about the ones that aren't.) A. ellipses B. hyperbolas C. parabolas D. circlesExplanation / Answer
X2-Y2-4Z=0
In XY plane, Z=0
Thus the equation becomes: X2-Y2 = 0 => X=+/- Y which is a line or lines. Therefore ans is F
In plane parallel to XY plane, Z= a ( constant )
Thus the equation becomes: X2-Y2 = constant which is a hyperbola. Therefore ans is A
In YZ plane, X=0
Thus the equation becomes: Y2 = 4Z which is a parabola. Therefore ans is E
In a plane parallel to YZ plane, X = Constant
Thus the equation becomes: Y2 - 4Z = constant which is a parabola. Therefore ans is C
In XZ plane, Y=0
Thus the equation becomes: X2 = 4Z which is a parabola. Therefore ans is F
In a plane parallel to XZ plane, Y = Constant
Thus the equation becomes: X2 - 4Z = constant which is a parabola. Therefore ans is C