f(x)=x2−3 and g(x)=x,
find f(g(x)).
x-3
Identify a,b,c for y=2x2−3x+5.
a=2,b=−3,c=5
Find the y-intercept of y=x2−5x+4.
(0, 4)
State the domain of y=x2−4x+3
(−∞,∞)
Rewrite y=x2−6x+11 in vertex form.
y=(x−3)2+2
f(x)=x2−3; g(x)=x
Find g(f(x))
g(f(x))=√(x2−3)
Does the parabola y=−3x2+4x−1y=−3x2+4x−1 open up or down?Why?
Down (since a=−3)
Find the x-intercepts of y=x2−9.
x=±3
Find the range of y=(x−4)2−9.
y≥−9
Write the vertex form of a parabola with vertex (2, –5) and a=1.
y=(x−2)2−5
f(x)=x2−3; g(x)=x
Write the function f∘g(x)f∘g(x) and state its domain.
f∘g(x)=x−3, domain: x≥0
Find the vertex of y=(x−2)2+7.
(2, 7)
Given y=−x2+6x−5, find the vertex.
x=3, y=4 → Vertex (3, 4)
Find the x-intercepts of y=2x2−8x+6
y=2(x2−4x+3)
→2(x−1)(x−3)
→x=1,3
Convert y=3x2−12x+8 to vertex form.
y=3(x−2)2−4
f(x)=x2−3; g(x)=x
Write the function g∘f(x) and state its domain.
g∘f(x)=√(x2−3),
domain: x2−3≥0
⇒x≤−√3 or x≥3
Find the vertex and axis of symmetry of y=2x2−8x+3.
Vertex (2, –5), Axis x=2x=2
Sketch a quick graph of y=(x+2)2−3 showing vertex and intercepts.
Vertex (–2, –3), opens up, y-int = 1
Determine the range of y=−x2+2x+3
Vertex (1, 4) → y≤4
For y=−2(x+3)2+1, list vertex, direction, and range.
Vertex (–3, 1), opens down, y≤1
f(x)=x2−3; g(x)=x
Evaluate f(g(16))
g(16)=4,
f(4)=42−3
=13
Write the equation of a parabola that opens down, has vertex (1, –2), and passes through (3, –10).
Plug in: y=a(x−1)2−2;
–10 = a(3–1)² – 2
→ –10 = 4a – 2
→ a = –2
→ y=−2(x−1)2−2
A parabola has vertex (1, –4) and passes through the point (3, 0). Write the equation of this parabola in vertex form.
Use y=a(x−1)2−4, plug in (3, 0):
0=a(3−1)2−4
⇒a=10
=a(3−1)2−4
⇒a=1
Equation: y=(x−1)2−4
Compare the graphs of y=x2+2 and y=−x2+2. State the vertex and range of each, then describe one difference between them.
For y=x2+2: Vertex (0, 2), opens up, range y≥2
For y=−x2+2: Vertex (0, 2), opens down, range y≤2
Difference: Same vertex, opposite directions; one has a minimum, the other has a maximum.
Find the axis of symmetry and vertex of y=−x2−4x−3 without completing the square.
x=−b/2a=−2, y=1 → Vertex (–2, 1)