Does anybody know how to solve this?​

Step-by-step explanation:

Given

The above triangle

Solving (a): AD

To solve AD, we consider triangle ACD.

Using cosine formula:

Where:

So:

Solving (b):  CD

Here, we make use of Pythagoras theorem:

So:

Solving (c): BD

Here, we make use of Pythagoras theorem:

the answer on e2020 is

10

4/5

3/5

4/3

step-by-step explanation:

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value