Question

if f(x)=log2 (x+4), what is f^-1(3)?

Answer 1

be clarify very well

Answer 2

solve below :-

3 = log2 ( x+4 )

Answer 3

ganeshie8's reply can be solved for x by raising 2 to the power 3 on the left side of the equation and to the power log2 (x+4) on the right side:

2^3 = 2^log2(s+4)

Since y=log2 x and y=2^x are inverses of each other, 2^log2(x+4) simplifies to x + 4.
Thus, 8 = x + 4. x + ?

Answer 4

Another, more roundabout, approach would be to actually find the inverse of y = base2log (x+4):
a) replace f(x) with y
b) interchange x and y (replace x with y and y with x)
c) solve the resulting equation for y
d) replace this y with

-1
f (x)
-1
e) The result is f (x) = 2^x -4..
f) evaluate this at x=3.