The distance graph shows the height of a plane as it completes a journey. When the plane is at a height of 38,000 feet (ft), it travels at a constant speed of 550 miles per hour. Check how long the ...

Inequalities that use < or > symbols are plotted with a dashed line to show that the line is not included in the region. Inequalities that use ≤ or ≥ symbols are plotted with a solid line to show that ...