If f(x) and f-1(x) are inverse functions of each other and f(x) = 2x+5, what is f-1(8)?
2 answers:
Answer:
B. 3/2
Step-by-step explanation:
When we have inverses, the input to one is the output of the other
f(x) = 2x+5
y = 2x+5
We want to find
f^ -1 (8)
So x becomes y and y becomes x in the inverse
That means we want y = 8 in the original function
8 = 2x+5
Subtract 5 from each side
8-5 = 2x+5-5
3 = 2x
Divide by 2
3/2 =x
This means the solution to
f^ -1 (8) = 3/2
Answer:
B. 3/2
Step-by-step explanation:
If f(x) and are inverse, that means that if we switch the x and y for f(x) and solve for y, we will get the inverse function.
Knowing that f(x) = 2x + 5, let's write this as y = 2x + 5 and switch the x and y:
x = 2y + 5
Now, solve for y:
x = 2y + 5
x - 5 = 2y
y = (x - 5)/2
That's the function:
Plug in 8 for x:
The answer is thus B.
<em>~ an aesthetics lover</em>
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Answer:
Step-by-step explanation:
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