Qualification > Math

Math P1 s07

(1/1)

mz:
can anybody please explain the concept behind question number 11, part ii?

immortal:
Find da inverse of f(x) dat is f-1(x)
Domain of f-1(x)=range of f(x) & vice-versa

nid404:

--- Quote from: mz on May 10, 2010, 02:56:30 pm ---can anybody please explain the concept behind question number 11, part ii?

--- End quote ---

here u go


Let f-1(x) = y
i.e. f(y) = x

x= 6/ 2y+3

2y+3=6/x
2y= 6/x -3
y= (6-3x)/2

thus f-1(x)= (6-3x)/2
y >= 0 implies that 6-3x >= 0 i.e.
6 >= 3x  i.e.  x <= 2
Thus the domain of f-1(x) is 0 <=  x  <= 2

mz:
thankyou so much both of you!!!!

Navigation

[0] Message Index