-x^2+4y^2-2x-16y+11=0?
A) Type of graph? (I think it s a hyperbola)
B) Write in standard form
C) center
D) vertices
E) foci
F) equation of asymptotes
回答 (1)
-x² + 4y² - 2x - 16y + 11 = 0
There is an x² term and a y² term, and they have different signs, so the graph is a hyperbola.
The y² is positive, so the hyperbola is vertical.
General equation for a vertical hyperbola:
(y-k)²/a² - (x-h)²/b² = 1
with
center (h,k)
vertices (h,k±a)
foci (h,k±c), c² = a²+b²
asymptotes y = ±(a/b)x + k∓(a/b)h
regroup terms
4y² - 16y - x² - 2x = -11
factor out the leading coefficients
4(y² - 4y) - (x² + 2x) = -11
complete the squares
4(y² - 4y + 2²) - (x² + 2x + 1²) = -11 + 4·2² - 1²
4(y-2)² - (x+1)² = 4
divide by the constant term, 4
(y-2)² - (x+1)²/4 = 1
(y-2)²/1² - (x+1)²/2² = 1
center (-1,2)
vertices (-1,2±1) = (-1,1) and (-1,3)
c² = 1² + 2² = 5
foci (-1,2±c) = (-1,2+√5) and (-1,2-√5)
asymptotes
y = -½x + 3/2
y = ½x + 5/2
收錄日期: 2021-05-01 20:34:10
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