Question

1. Let f(x) = x2 – 81. Find f–1(x).
2. Let f(x) = x + 2 and g(x) = x2 – 6x + 3. Find g(f(x)).
3. Let f(x) = x – 3 and g(x) = x + 11. Find f(x) • g(x).
4. Let f(x) = x2 – 3x – 7. Find f(–3).
5. Let f(x) = x2 + 2x – 5 and g(x) = x + 6. Find f(x) + g(x).
6. Let f(x) = x2 – 2x + 2 and g(x) = x – 3. Find f(x) • g(x).
7. Let f(x) = –4x + 7 and g(x) = 10x – 6, find f(g(x)).
8. Let f(x) = 5x + 12. Find f–1(x).
9. Let f(x) = x – 2 and g(x) = x2 – 7x – 9. Find f(g(–1)).
10. Let f(x) = 3x2 + x – 3 and g(x) = x2 – 5x + 1. Find f(x) – g(x).

Answer 1

are u sure that da questions (1) & (8) are correct?
anyway
(2) just f(x) for x in g(x)
i.e
g(f(x)) = (x+2)^2 - 6(x+2) +3
question (7) also can be solved in the same way.
(3). f(x).g(x) = f(x)*gx)
= (x-3)(x+11)
= x^2+8x-33
(4). just substitute (-3) for x
(5). just add the two functions
(6). same procedure as in (3)
(7). same as in (2)
(9). first substitute (-1) for x in g(x) and find g(-1)
then substitute the value obtained for g(-1) for x in f(x)
(10).subtract g(x) from f(x)

Answer 2

Thanks!