Question

...Given f(x)= X ^2 and g(x)= 2^x
a) the inverse of g is a function, but the inverse of f is no a function. Explain why this statement is true.
b) Find g ^-1(f (3) ) to the nearest tenth

please help! i really tried to do it but i can't find a similar problem in my notes :SS

Answer 1

HEYYYYY

Answer 2

Help plz

Answer 3

With a function, it works this way: you put in a number, do the math and out comes another number.

With 2^x it is just like this. The reverse is also true: if you have some number that is the outcome of 2^x, there is always just one x with which you started.
E.g: 2^3=8. If you work back from 8 you only get 2.

With x^2 it is just a little different: you put in 2, out comes 4. No problem.
But if 4 is an outcome, you have to choose between two numbers: it could that you put in 2, but it also could have been -2: (-2)^2 =4.

x^2 has no inverse, because you do not have a unique origin of a number.
Compare this with 2^x...

Answer 4

okay thanks...

Answer 5

(:..
thanks a lot.

Answer 6

yw! Hope you understand now...

Answer 7

kind of...who cares i never really understood it..