graphing
Find intersections of two graphs online
Plot two expressions in Graph Lab, enable points of interest, and trace to read intersections—open the demo with y = x² − 2 and y = x + 1 already loaded.
By UtilBloom · Published 2026-10-12 · Updated 2026-10-12
The problem
Solving systems graphically means finding where two curves meet. Algebra alone may miss extraneous roots; a plot confirms which solutions are real in the viewport.
How to read intersections in Graph Lab
Add two expression rows, enable show POI / trace, and click nearby markers to read coordinates. Zoom near crossings if sampling is coarse. Open the intersection demo.
When to use a solver instead
Use /math/equation-solver or a system solver for exact algebra. Use the light /math/graphing-calculator for a quick two-curve sketch without POI tooling.
FAQ
Are POI values exact?
They are numeric samples—treat them as approximations and confirm with algebra when the grade requires exact answers.
What if curves barely touch?
Zoom in; tangency can look like a miss at coarse sampling.
Can I find intersections of implicits?
Implicits and inequalities may need careful zoom; prefer explicit pairs when possible.
Does this replace Desmos?
No for Classroom activities. Yes for private intersection checks beside UtilBloom tools—see /compare/desmos.