Test algebraically to determine whether the equations graph
Solution
Given equation is X2 - Y2 = 81.
Checking whether the graph is symmetric about X-axis:
If Y= -Y in the equation results in the original equation then the graph is symmetric is about X-axis.
X2 - Y2 = 81.
X2 - (-Y)2 = 81.
X2 - Y2 = 81.
Therefore, the given equation\'s graph is symmetric about X-axis.
Checking whether the graph is symmetric about Y-axis:
If X= -X in the equation results in the original equation then the graph is symmetric is about Y-axis.
X2 - Y2 = 81.
(-X)2 - Y2 = 81.
X2 - Y2 = 81.
Therefore, the given equation\'s graph is symmetric about Y-axis.
Checking whether the graph is symmetric about origin:
If X=-X and Y= -Y in the equation results in the original equation then the graph is symmetric is about origin.
X2 - Y2 = 81.
(-X)2 - (-Y)2 = 81.
X2 - Y2 = 81.
Therefore, the given equation\'s graph is symmetric about origin.
So, second option is correct which is that the graph is symmetric about X-axis, Y-axis and origin.
