The three mistakes are:
1) Interchanging the variable x and y is incorrect.
2) Student need to use ± sign.
3) The domain of the function is incorrect it should be x ≤ 0.
Step-by-step explanation:
Consider the provided steps.
The first step is wrong interchanging the variable x and y should be:
The step 4 is wrong because student need to use ± sign. The another mistake is the domain of the function is incorrect.
Because the radicand should be greater or equal to 0.
For which x must be less than or equal to zero. It should be x ≤ 0.
Sample 1.The student did not switch both instances of x with y. He should have written x = y2 + 12y.
2.He wrote only the principal square root instead of using the ± sign.
3.The domain is incorrect. For the radicand to be greater than or equal to zero, x must be less than or equal to zero. It should be x ≤0.
Step-by-step explanation: For sure enjoy!