QUESTION 21 Differential a) Let f(x) be defined as follows f(x) = tan x First find the differential df Then evaluate df when a = (pi)/3 and (delta)x = (pi)/18. %3D b) Let g(x) be defined as follows { g(x) = sqrt[ x^2 + 1] } First find the differential dg Then evaluate dg when a = 2 and (delta)x = 0.3. c) Use differential to give a linear approximation to /50 { sqrt(50) } Apply the ideas of differentials to f(x) = sqrt(x), where a = 49. %3D