A system of equations asks for values that satisfy both equations. A squared variable can give two possible solutions, so graph both equations in Desmos and click their intersections. Use a condition such as positive to choose the right point, then calculate what the question asks for. Finding the point isn't the same as finding a product of its coordinates.
Hints
- Hint 1
A square root undoes squaring. A positive number and its negative can have the same square, so look for both possible -values before using the condition on .
- Hint 2
An intersection is a point that satisfies both equations. Its first coordinate is and its second is . After choosing the point with positive , what does ask you to do with those coordinates?
Step-by-step
Graph the system and choose the point
Step 1Find the solution with positive x
Type and on separate Desmos lines, then click their two intersections. An intersection satisfies both equations. Desmos shows and . The first coordinate is , so only has positive .
- Step 2
Multiply the coordinates
At , means multiply and , not add them. Type on a new Desmos line; it shows . Choose the point that meets the condition before calculating the requested expression. So . Choice C.