A squared expression can equal a positive number in two ways: the expression can be positive or negative. If the question asks for one possible value, you don't need to find both. A Desmos regression can solve the equation directly; when every choice is positive, restrict it to positive values. Don't confuse the number being squared with the result of squaring it.
Hints
- Hint 1
A square root of is a number whose square is . Both and work, so what two values could the expression inside the parentheses have?
- Hint 2
A Desmos regression finds a value that makes two sides match, but it may find only one solution. Since every choice is positive, what restriction would make it look for a positive value?
Step-by-step
Use the square, then a Desmos regression
Step 1Identify the two values that could be squared
Because and , the squared expression could equal either number:
Both and square to . Don't set : is the result of squaring, not the number being squared.
- Step 2
Find a positive possible value
Every answer choice is positive, so restrict Desmos to positive values. Type . Replace with because Desmos solves for a subscripted variable in a regression; tells it to match the two sides. Under PARAMETERS, Desmos shows . So is a possible value. Choice C.