How this calculation works
Find break-even quantities when one plan changes its marginal rate at a threshold.
Solve A=B on each interval and retain only roots within that intervalA worked example
A=20+2q. B=10+4q through 10 units and 40+q thereafter. They meet at 5 and 20.
Good to know
The later rate applies only to units beyond the threshold.
Reference: OpenStax Algebra and Trigonometry (opens in a new tab) ↗
Read the result
Find break-even quantities when one plan changes its marginal rate at a threshold.
The primary result is labeled “Number of break-even quantities”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
The later rate applies only to units beyond the threshold.
For a related exercise, try the quadratic equation solver.
A few questions, answered
How can I check the default inputs by hand?
A=20+2q. B=10+4q through 10 units and 40+q thereafter. They meet at 5 and 20.
Which rule does this calculator apply?
Solve A=B on each interval and retain only roots within that interval