64.2k views
4 votes
Please help, I’m not good at math

Please help, I’m not good at math-example-1

1 Answer

2 votes

Explanation:

a regular function finds the functional result y to a given x value.

the inverse function finds the original x to a given y value.

g^-1(1) is therefore the x-value, so that g(x) = 1.

so, we look through the value pairs. where do we find y = 1 ? ah, in the pair (9, 1).

x = 9 lead to the functional result y = 1.

therefore, g^-1(1) = 9

h(x) = y = -3x - 14

in other words, h(x) expresses y in terms of x.

h^-1(x) expresses x in terms of y.

so, we want to transform the functional equation, so that it says "x = ...." :

y = -3x - 14

y + 14 = -3x

x = (y + 14)/-3

and to turn it into regular function notation, we rename x to y and y to x :

y = h^-1(x) = (x + 14)/-3 = (-1/3)(x + 14)

(h○h^-1)(x) = x

always.

in that process we find first what original input value for h lead to the value of x. and then we use that as input value for h. and, of course, we have to get x as result.

to check here in our case

(h○h^-1)(-5) = -5

h^-1(-5) = (-5 + 14)/-3 = 9/-3 = -3

h(-3) = -3×-3 - 14 = 9 - 14 = -5

there you have it.

User LTR
by
7.0k points