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Given f(x) = -5x + 2, determine each of the following:

a) f(-1)

b) f^-1(7)

c) f^-1(-43)

User Kato
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1 Answer

6 votes

Answer:

a) 7

b) -1

c) 9

Explanation:

a) Substitute -1 into the x's of the function.

f(-1) = -5(-1) + 2

f(-1) = 5 + 2

f(-1) = 7

b) f^-1(7) means: find the inverse of the function with 7 substituted as x.

Let y = f(x)

y = -5x + 2

5x = 2 - y

x = 2 - y / 5

f^-1(x) = 2 - x / 5

f^-1(7) = 2 - 7 / 5

f^-1(7) = -5/5

f^-1(7) = -1

c) We have already found the inverse of the- original function. Substitute -43 into the x's of the inverse function.

f^-1(-43) = 2 - (-43) / 5

f^-1(-43) = 2 + 43 / 5

f^-1(-43) = 45/5

f^-1(-43) = 9