1. (a) 2ex (b) 2x - ex (c) - 5e-5x (d) 5/x (e) 2/x (f) -1/x
2. (a) ex - 2 with the value -1 at x = 0.
(b) 2x + 2ex
with the value 18.78 at x = 2.
(c) ex(x3
+3x2 -2) with the value 5.437 at x = 1.
3. These are to practice the function of a function rules (Chain Rule). The important thing is the differentiation, not necessarily the simplification afterwards.
(a) 2(3x + 1).3 = 6(3x + 1)
(b) ½(2x4 - 5)-½(8x3)
=
(c) x.3(2x + 3)2.2 + (2x + 3)3 = 6x(2x + 3)2 + (2x + 3)3
(d) x2.½(x-2)-½.1
+ 2x(x-2)½ =
(e) { (x+2).1 - (x+1).1 } / (x+2)2 = 1 / (x+2)2
(f)
(g)
(h) 5exp (x2 + 1).2x = 10x exp(x2 + 1)
(i) -5(ln (3x + 1)-2).
=
4.
The stationary value of N(ν) is therefore given by equating the factor in the [ ] to zero which leads to:
Examination of the distribution function itself shows that it is a product of a function ν2 which rises with increasing ν and a function exp(-Bν2) which falls with increasing ν, both being positive functions. This stationary point must therefore be a maximum. Substitution of the given values of the parameters then leads to a most probable speed of ν = 422 m/s. You might like to draw out this function to show them what it looks like...