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Consider the function. what is the x-intercept of f–1(x)?

User Ege Bayrak
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The x intercept of f-1(x) is the y intercept of f(x). The y intercept of f-1(x) is the x intercept of f(x). A horizontal asymptote for f(x) produces a vertical asymptote for f-1(x). A vertical asymptote for f(x) produces a horizontal asymptote for f-1(x).

(2 1/2, 0)

f(x) = 2 1/2 - 3 1/3 * x

or

f(x) = 5/2 - (10/3)*x

f^-1(x) is the inverse of f(x), which is obtained replacing f(x) by x, and x by y, and solving for y, as follows:

x = 5/2 - (10/3)*y

(10/3)*y = 5/2 - x

y = (5/2)*(3/10) - x*(3/10)

y = (3/4) - (3/10)*x

f^-1(x) = (3/4) - (3/10)*x

at x-intercept, f^-1(x) = 0,

(3/4) - (3/10)*x = 0

(3/4) = (3/10)*x

x = (3/4)*(10/3)

x = 5/2 or 2 1/2

User Dodd
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