The total weight of the Italian sandwich in its simplest fraction is 3/5.
meat : 0.35 in fraction 35/100
veggies : 0.15 in fraction 15/100
sauce : 0.05 in fraction 5/100
bread : 0.05 in fraction 5/100
Total weight = 35/100 + 15/100 + 5/100 + 5/100
= (35 + 15 + 5 + 5) / 100
= 60/100
To simplify the fraction:
60/100 ⇒ 60 ÷ 10 = 6 ; 100 ÷ 10 = 10 ⇒ 6/10
6/10 ⇒ 6 ÷ 2 = 3 ; 10 ÷ 2 = 5 ⇒ 3/5
1,100.226 is your answer :)
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)]