Answer:
<em>f</em> has no critical points.
Step-by-step explanation:
We are given:

A function has critical points whenever its derivative equals 0 or is undefined.
Differentiate the function:

Since this will never be undefined, solve for its zeros:

Hence:

Recall that the value of sine is always between -1 and 1.
Thus, no real solutions exist.
Therefore, <em>f</em> has no critical points.
An easy way to do this question is finding 40% of 120 then subtracting it from $120. This is done in a few ways, i use the unitary method:
120/100= 1% =1.2
x40 to find 40% = $48
120-48= 72
The sale price is 72
OR
multiply 120 by .6 to find the result with 40% taken away
Answer:
-10
Step-by-step explanation: