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X^2+y-9=0 test for symmetry

User Ness
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1 Answer

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We have three tests of symmetry. In respect to the y-axis or in respect to the x-axis, or in respect to the origin.

For symmetry with respect to the Y-Axis, check to see if the equation is the same when we replace x with −x:


x^2+y-9=(-x)^2+y-9=0

Since the equation remains the same when we change the sign of the x variable, the equation is symmetric in respect to the y-axis.

For symmetry with respect to the X-Axis, check to see if the equation is the same when we replace y with −y:


x^2+y-9\\e x^2+(-y)-9=x^2-y-9

Since the equation does not remains the same when we change the sign of the y variable, the equation is not symmetric in respect to the x-axis.

The equation is symmetric with respect to the origin if for every point (x,y) that satisfies the equation, the point (-x, -y) also satisfies the equation.


(-x)^2+(-y)-9=x^2-y-9\\e x^2+y-9

Since it doesn't satisfies this condition, the equation is not symmetric with respect to the origin.

User Kcsquared
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