once you position them on a graph you want to have a scale that shows the values of x and y. You study and list the values of (x, y) at 3 separate aspects call the elements (x1, y1), (x2, y2), and (x3, y3) y = a x^2 + b x + c once you position each and each and every aspect into the equation you get an equation in a, b and c. you presently have 3 equations to clean up concurrently to stumble on a, b, c.
Answers & Comments
Verified answer
If the equation is x as a function of y, then the parabola is vertically oriented.
If the coefficient of the x² term, 'a,' is positive, the parabola opens upward.
If the coefficient of the x² term is negative, the parabola opens downward.
If the equation is y as a function of x, the parabola is horizontally oriented.
If the coefficient of the y² term is positive, the parabola opens to the right.
If the coefficient of the y² term is negative, the parabola opens to the left.
...........................................
1.) x = (y - 5)² + 1
Opens to the right.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Vertex (1, 5)
¯¯¯¯¯¯¯¯¯¯¯
h = 1
k = 5
a = 1
p = 1 / 4a
p = 1/4
Focus (Fx, Fy)
Fx = h + p
Fx = 1 + 1/4
Fx = 5/4
Fy = k
Fy = 5
Focus (5/4, 5), or
Focus (1.24, 5)
¯¯¯¯¯¯¯¯¯¯¯¯¯
2.) y = 2(x + 3)² - 4
Opens upward.
¯¯¯¯¯¯¯¯¯¯¯¯¯
Vertex (- 3, - 4)
¯¯¯¯¯¯¯¯¯¯¯¯¯
h = - 3
k = - 4
a = 2
p = 1 / 4(2)
p = 1/8
Fx = k + p
Fx = - 4 + 1/8
Fx = - 32/8 + 1/8
Fx = - 28/8
Fx = - 7/2
Fy = h
Fy = - 3
Focus (- 7/2, - 3), or
Focus (- 3.5 - 3)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯
3.) y = - 2x + 1
Straight Diagonal line; no vertex; no focus.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
4.) y = x² - 6x + 10
Opens upward.
¯¯¯¯¯¯¯¯¯¯¯¯¯
y = (x² - 6x) + 10
y = (x² - 6x + 9) + 10 - 9
y = (x - 3)² + 1
Vertex (3, 1)
¯¯¯¯¯¯¯¯¯¯¯
h = 3
k = 1
a = 1
p = 1/4
Fx = h
Fx = 3
Fy = k + p
Fy = 1 + 1/4
Fy = 4/4 + 1/4
Fy = 5/4
Focus (3, 5/4), or
Focus (3, 1.25)
¯¯¯¯¯¯¯¯¯¯¯¯¯
5.) x = 3y² + 6y + 11
Opens to the right.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
x = (3y² + 6y) + 11
x = 3(y² + 2y) + 11
x = 3(y² + 2y +1) + 11 - 1
x = 3(y + 1)² + 10
Vertex (10, - 1)
¯¯¯¯¯¯¯¯¯¯¯¯¯
h = 10
k = - 1
a = 3
p = 1 / 4(3)
p = 1/12
Fx = h + p
Fx = 10 + 1/12
Fx = 120/12 + 1/12
Fx = 121/12
Fy = k
Fy = - 1
Focus (121/12, - 1, or
Focus (10.0833, - 1)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
once you position them on a graph you want to have a scale that shows the values of x and y. You study and list the values of (x, y) at 3 separate aspects call the elements (x1, y1), (x2, y2), and (x3, y3) y = a x^2 + b x + c once you position each and each and every aspect into the equation you get an equation in a, b and c. you presently have 3 equations to clean up concurrently to stumble on a, b, c.