Check the functions whose inverses are also functions. a. On a coordinate plane, an absolute value function opens down.
b. On a coordinate plane, an exponential functions increases from quadrant 2 into quadrant 1.
c. On a coordinate plane, a cubic function has an x-intercept of (0, 0).

 B and C.

Step-by-step explanation:

A function will have an inverse, only and only if every value of y can be linked to only one value x.

A) Here we have an absolute value:

We know that for example:

I5I = 5 and I-5I = 5.

Then an absolute value function can not have an inverse function.

B) one way of having a function that is invertible or not, is see if the function is increasing or decreasing.

If a function is, for example, increasing, then as the value of x increases, also does the value of y.

Then we will never see that a single value of y is related to two or more different values of x.

Then an exponential function, which is an increasing function, will have an inverse that is also a function.

C) A cubic function that has a root in (0,0)

The cubic function that has only one root at x = 0 is the function:

f(x) = a*x^3 + b*x

where a and b are real numbers of the same sign.

Now, we can see at the first derivate of f(x) to see if it is strictly increasing or strictly decreasing.

f'(x) = 3*a*x^2 + b

Ok, as x^2 is always positive, we can know that the sign of f'(x) will always be the same, so this function is strictly increasing or strictly decreasing (it depends on the signs of a and b).

Then this function has an inverse that is also a function.

idk

step-by-step explanation:

use that smart brain