Question

Assume that x = 5.2 ± 0.1 and y = 3.8 ± 0.2. Calculate the following expressions, including the errors. Keep only one significant digit in the error.
A) p = xy

B) u = x/y2

C) v = √(x3y5)

Answer 1

5.3 * 4.0 = 21.2 biggest
5.2 * 3.8 = 19.76 middle
difference = 1.44 which is 1 to one sig figure
19.8 +/- 1
etc

Answer 2

B) u = x/y2
assume you mean u = x / y^2
for this to get the biggest use big x and small y
5.3 / (3.8 -.2)^2 = 5.3 / 3.6^2

Answer 3

If you want to be really fussy you can use average of biggest and smallest +/- half of difference