Answer:
The equation for a parabola with vertex at the origin and a directrix at x = 1/48 is 
.
Step-by-step explanation:
As directrix is a vertical line, the parabola must "horizontal" and increasing in the -x direction. Then, the standard equation for such geometric construction centered at (h, k) is:
Where:
, 
- Horizontal and vertical components of the location of vertex with respect to origin, dimensionless.
- Least distance of directrix with respect to vertex, dimensionless.
Since vertex is located at the origin and horizontal coordinate of the directrix, least distance of directrix is positive. That is:
Now, the equation for a parabola with vertex at the origin and a directrix at x = 1/48 is .
Answer:
All your steps are correct. Well done!
Answer:
In inequality notation:
Domain: -1 ≤ x ≤ 3
Range: -4 ≤ x ≤ 0
In set-builder notation:
Domain: {x | -1 ≤ x ≤ 3 }
Range: {y | -4 ≤ x ≤ 0 }
In interval notation:
Domain: [-1, 3]
Range: [-4, 0]
Step-by-step explanation:
The domain is all the x-values of a relation.
The range is all the y-values of a relation.
In this example, we have an equation of a circle.
To find the domain of a relation, think about all the x-values the relation can be. In this example, the x-values of the relation start at the -1 line and end at the 3 line. The same can be said for the range, for the y-values of the relation start at the -4 line and end at the 0 line.
But what should our notation be? There are three ways to notate domain and range.
Inequality notation is the first notation you learn when dealing with problems like these. You would use an inequality to describe the values of x and y.
In inequality notation:
Domain: -1 ≤ x ≤ 3
Range: -4 ≤ x ≤ 0
Set-builder notation is VERY similar to inequality notation except for the fact that it has brackets and the variable in question.
In set-builder notation:
Domain: {x | -1 ≤ x ≤ 3 }
Range: {y | -4 ≤ x ≤ 0 }
Interval notation is another way of identifying domain and range. It is the idea of using the number lines of the inequalities of the domain and range, just in algebriac form. Note that [ and ] represent ≤ and ≥, while ( and ) represent < and >.
In interval notation:
Domain: [-1, 3]
Range: [-4, 0]
Y = -2x + b
Plug in the point
7 = -2(-1) + b
7 = 2 + b
b = 5
Final equation y = -2x + 5
