Question
Question: How do you find the vertex and the intercepts for \[x = \dfrac{1}{{ - 32}}{y^2}\]?...
How do you find the vertex and the intercepts for x=−321y2?
Solution
We can find the vertex and intercepts of the equation by their general formulas obtained and to find the y-intercept of the given equation, just we need to substitute x= 0 in the given equation and solve for y and to find the x-intercept of the given equation, just we need to substitute y = 0 in the given equation and solve for x.
Complete step by step solution:
The given equation is
x=−321y2.
The given equation is in the form of x=ay2+by+c, in which we need to find the vertex of x and y coordinate.
As the coefficient of y2is negative, considering equation y=ax2+bx+c the b from bx moves the graph left or right in that
xvertex=(−21)×b
Now considering equation x=ay2+by+c the b from by moves the graph up or down in that
yvertex=(−21)×b
However, we get b=0, so the axis of symmetry coincides with the x-axis.
Hence, y-intercept is at x=0.
Substitute the value of x in the given equation as
x=−321y2
0=−321y2
⇒y=0
Therefore, as there is only a single value as it does not cross the y-axis but y-axis is tangential to the vertex.
Hence, the vertex of x and y is (0,0).
The intercepts are only at one point i.e., at the origin and the axis of symmetry is the x-axis i.e., y = 0.
Note:
As per the given equation consists of x and y terms based on the intercept asked, we need to solve for it. For ex if y-intercept is asked substitute x=0 and solve for y and if x-intercept is asked substitute y=0 and solve for x and the y-intercept of an equation is a point where the graph of the equation intersects the y-axis.