She would start at the 3 inch mark and count from there.
Answer:
5(2+8)+(12-6/3)2
5(10)+(12/1-6/3)2
50+(36/3-6/3)2
50+(30/3)2
50+60/3
50+20
70
Step-by-step explanation:
For simplicity, dy/dx means f'(x);
We have y = ( 8 - x^2 ) / 2x;
Then, y = 4/x - x/2;
So, f'(x) = (4/x - x/2)' = (4/x)' - (x/2)' = -4/(x^2) -1/2 because we use <span> d<span>ifferentiation formulas, such as : (f+g)' = f' + g'; (cf)' = cf'; x'=1; (1/x)' = -1/(x^2);
</span></span>Finally, f'(4) = -4/16 -1/2 = -4/16 - 8/16 = -12/16 = -3/4.
The correct answer is E.