0.88......ones (decimal), tenths, hundredths
so 8 is in the tenths place....8/10
The answer to that will be the letter c , 24ft
You would keep the 2 hour for the whole number of the mixed number and then, make the minutes (15) as a fraction with 60, and divide them both by 20. that is just for the mixed number.
It's hard to type and hard to read the "inverse tangent" function, as you've seen (above).
So, use "arctan x" instead.
Then the problem becomes: "differentiate cos (arctan x)."
You must apply first the rule for differentiating the cosine function, and next apply the rule for differentiating the arctan function:
(d/dx) cos (arctan x) = - sin (arctan x) * [1/(1+x^2)]
