With two lines describing height at each time, you're working with a system of linear equations. Equal heights at the same time appear where the lines cross. Type both equations into Desmos and click their intersection to read the shared point. Check which axis the question asks for: time is the first coordinate, while height is the second.
Hints
- Hint 1
An intersection is a point shared by two graphs. At that shared point, both drones have the same time and the same height. Where do you see that point on the graph?
- Hint 2
In a point written , the first coordinate is . Here measures time and measures height. Which coordinate will answer the question once you find the crossing?
Step-by-step
Read the lines' intersection
Step 1Identify what the crossing means
The drones have the same height at the same time where their lines cross. That crossing is an intersection, a point on both lines. Read the -coordinate for time, not the -coordinate for height.
- Step 2
Find the time in Desmos
Type and on separate lines in Desmos, then click where they cross. Desmos shows . The first coordinate is time, so the drones are at the same height after seconds. The is their height in meters, not the time. Choice B.