SOLUTION: Draw the graph. 4y^2 +9y+10 = x

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Question 468040: Draw the graph. 4y^2 +9y+10 = x

Found 2 solutions by ewatrrr, ccs2011:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 
Hi,
the vertex form of a parabola opening right or left, x=a%28y-k%29%5E2+%2Bh where(h,k) is the vertex.
4y^2 +9y+10 = x
4[(y + 9/8)^2 - 81/64] + 10
4(y + 9/8)^2 - 81/16 + 10 = x
4(y + 9/8)^2 + 79/16 = x V(79/16,-9/8) Opening to the right


Answer by ccs2011(207) About Me  (Show Source):
You can put this solution on YOUR website!
This is a horizontal or sideways parabola because it is solved for x and the y is squared.
To graph this first determine vertex then a 2nd point.
To determine the vertex of this parabola there are 2 methods:
- Use completing the square to put it in vertex form:
x+=+a%28y-k%29%5E2+%2B+h where (h,k) is vertex
- Use formula y=%28-b%29%2F2a where x=+ay%5E2+%2B+by+%2B+c to determine line of symmetry then substitute this value into equation to determine x_value of vertex.
I will use the 2nd since it is the more straightforward and I don't know how familiar you are with completing the square.
x+=+4y%5E2+%2B9y+%2B10
a = 4
b = 9
c = 10
y=%28-b%29%2F2a+=+%28-9%29%2F8
Substitute this back in and solve for x
x+=+4%28-9%2F8%29%5E2+%2B9%28-9%2F8%29+%2B10
x+=+4%2881%2F64%29+-%2881%2F8%29+%2B10
x+=+%2881%2F16%29+-%2881%2F8%29+%2B10
x+=+%2881%2F16%29+-%28162%2F16%29+%2B%28160%2F16%29
x+=+%2881-162%2B160%29%2F16+=+79%2F16
Vertex: (79%2F16,%28-9%29%2F8)
Now we need one other point to graph this parabola
Lets look at x_intercept, if y=0 then x =10, (10,0)
A parabola is symmetric so if we go 9%2F8 in other direction x will also be 10
(10,%28-18%29%2F8)
Now plot these 3 points and draw a parabola that goes through all 3 points
Here is a graph:
**Imagine its rotated clockwise 90 degrees, it wont do horizontal parabolas**
graph%28300%2C300%2C-6%2C4%2C0%2C12%2C4x%5E2%2B9x%2B10%29