Tuesday, October 24, 2006
Year 13 Hints
1 a What is cos x? b What is sin x?
2 Find 3x first.
3 Use the appropriate identity to produce a quadratic in tan x.
4 See the examples before exercise 7D.
5 Multiply both the numerator and denominator by sin x.
6 Use the double angle formulas. Use the appropriate versions of cos 2x so that the ones cancel.
7 Factorise both the numerator and denominator.
8 Factorise and then write with a common denominator.
9 a You can't simplify fg(x).
b Swap x and y, then rearrange. c ditto!
10 This is a quadratic equation.
11 Is there an asymptote?
12 Remember: for an inverse to exist every value of y must have only one value of x.