Recall the inverse function theorem: if f(x) has an inverse, and if f(a) = b and a = f⁻¹(b), then
f⁻¹(f(x)) = x ⇒ (f⁻¹)'(f(x)) • f'(x) = 1 ⇒ (f⁻¹)'(f(x)) = 1/f'(x)
⇒ (f⁻¹)'(b) = 1/f'(a)
Let b = 10. Then pick the function f(x) such that f(a) = 10 and f'(a) = -8 for some number a.
Answer:
It will take 5 weeks for you and your friend to have the same balance
Step-by-step explanation:
Let
Your savings expression be
135 + 12x
Your friends savings expression
95 + 20x
Where,
x = number of weeks for you and your friend to have the same balance
Equate the two expressions
135 + 12x = 95 + 20x
Collect like terms
135 - 95 = 20x - 12x
40 = 8x
Divide both sides by 8
40/8 = x
x = 40/8
= 5
x= 5 weeks
Check
Your savings expression
135 + 12x
135 + 12(5)
=135 + 60
= $195
Your friends savings expression
95 + 20x
95 + 20(5)
= 95 + 100
= $195
Therefore, It will take 5 weeks for you and your friend to have the same balance
Answer:
12.6
Step-by-step explanation:
