Answer:
2.6
Step-by-step explanation:
by similar property

The salary before the increase was $48000.
<span><u><em>The correct answer is:</em></u>
$42.
<u><em>Explanation:</em></u>
The best way to find a total bill including tip (or tax if that is what you are looking for - it is found the same way), is to multiply the original total by 1 + the percentage of the tip.
Since the percentage is 20%, we add 0.20 to 1 to get 1.20.
Now we multiply that by the original cost to get the final answer.
1.20*35 = 42</span>
Answer:
(f⁻¹)'(b) = 1/f'(f⁻¹(b)) = 1/f'(a)
Step-by-step explanation:
The function f⁻¹(x) is the reflection of the function f(x) across the line y=x. Every point (a, b) that is on the graph of f(x) is reflected to be a point (b, a) on the graph of f⁻¹(x).
Any line with slope m reflected across the line y=x will have slope 1/m. (x and y are interchanged, so m=∆y/∆x becomes ∆x/∆y=1/m) Since f'(x) is the slope of the tangent line at (x, f(x)), 1/f'(x) will be the slope of the tangent line at (f(x), x).
Replacing x with f⁻¹(x) in the above relation, you get ...
... (f⁻¹)'(x) = 1/f'(f⁻¹(x)) will be the slope at (x, f⁻¹(x))
Putting your given values in this relation, you get
... (f⁻¹)'(b) = 1/f'(f⁻¹(b)) = 1/f'(a)