Question

Diketahui f (x) = 2/x
f o g (x) = 3x/x-2
ditanya g-1 (x) = ????

Answer 1

1. f(-2) = (-2)^2 + 3(-2) + 4 = 4 - 6 + 4 = 2
2. g(x+1) = 4(x+1)/(x+1)-5 = (4x+4)/(x-4)
3. (g o f)(x) = 1+ 1/f(x) = 1 + 1/(x/x-1) =
= 1 + 1 . (x-1) / x
= 1 + (x-1) /x
= (x + x - 1)/x
= (2x -1)/x

4. (f o g)(x) = g(x) - 5 = x²+2x+1 - 5 = x²+2x-4
maka (f o g)(4) = 4^2 + 2(4) - 4 = 16 + 8 - 4 = 20

5. (f o g)(x) = 5x²-4, dan f(x)= x+7
maka g(x) + 7 = 5x²-4 , dengan demikian diperoleh
g(x) = 5x² - 11. yg ditanya f(6) atau g(6)?!

6. (f o g)(x) = 3x-1/2x-3 dan g(x)=5x-4 , maka
f(x) = 3x+7 / 2x-7 (pakai rumus fungsi f(x) = ax+b/cx+d)
maka f(6) = 3(6) + 7 / 2(6) - 7 = 25/5 = 5

7. (f o g)(x) = g(x) + 3 = (2x+1/3x+4) + 3 = (11x+13)/(3x+4)

8. (f o g)(x) = 2(x²+1)-5 = 2x² - 3
maka (f o g)(2) = 2(2)² - 3 = 5

9. a. (f o g)(x) = (3x-5)²+1 = 9x²-30x+25+1 = 9x²-30x+26
b. (g o f)(x) = 3(x²+1)-5 = 3x²+3 - 5 = 3x²-2

10. (g o f)(x) = (3x+4)²+1 = 9x²+24x+17
maka (g o f)(-1) = 9(-1)²+24(-1)+17 = 9 - 24 + 17 = 2

Answer 2

DIk f o g = 

      f (x) = 
Dit g - ?
jawab.

f o g = 



g = 

jadi nilai g (x) = 2/3

maka g- nya = - 3/2