Let

f={(−1,1),(0,4),(4,0)}

and

g={(−1,−3),(1,7),(4,2),(5,−9)}.

Find g/f and state its domain.

in Calculus Answers by

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

The way I approached this initially was to work out the quadratic that fits the given points in f(x) and the cubic that fits the given points in g(x).

f(x)=-4x²/5+11x/5+4, g(x)=-x³/6-2x²/3+31x/6+8/3.

f(x)=(-4x²+11x+20)/5, g(x)=(-x³-4x²+31x+16)/6.

f(x)/g(x)=(6/5)(-4x²+11x+20)/(-x³-4x²+31x+16).

However, there may be other curves fitting the given points, so we should examine how else we can look at the problem. The set of points for g is larger than that for f, and there are only two points having the same x coordinate in each set. This reduces f(x)={ (-1,1), (4,0) } and g(x)={ (-1,-3), (4,2) }.

f(x) and g(x) are effectively y values, so f/g is a comparison of y values, that is, y coordinates for common x coordinates.

From this f/g={ -⅓, 0 }. We can’t compare f and g for the other points because they do not share x coordinates. The domain for f/g is { -1, 4 }, whereas the domain for f is { -1, 0, 4 } and for g is { -1, 1, 4, 5 }.

by Top Rated User (1.1m points)

Related questions

1 answer
asked Mar 19, 2013 in Algebra 2 Answers by anonymous | 1.6k views
Welcome to MathHomeworkAnswers.org, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
87,551 questions
99,638 answers
2,417 comments
442,208 users