No.148 Range of a Linear Function
POINT
With a positive slope, \(y\) increases as \(x\) increases. With a negative slope, \(y\) decreases as \(x\) increases.
Example
1
For \(y=2x+1\), find the range of \(y\) when \(-2\le x<3\).
\(-3\le y<7\)
2
For \(y=-2x+4\), find the range of \(y\) when \(-1<x\le2\).
\(0\le y<6\)
TRY
TRY 1
For \(y=3x-2\), find the range when \(0\le x<4\).
\(-2\le y<10\)
TRY 2
For \(y=-x+5\), find the range when \(-2<x\le3\).
\(2\le y<7\)