You're right, sthamntungwa! Let's list out more specific points for plotting to make your graph even clearer.
Here are the calculations and coordinates for plotting f(x), f−1(x), and the line y=x.
1. Line of Reflection: y=x
This line passes through points where the x-coordinate equals the y-coordinate.
- (0,0)
- (1,1)
- (2,2)
- (3,3)
- (4,4)
- (5,5)
- (6,6)
- (7,7)
2. Graph of f(x)=2x−5
The domain for f(x) is {x:0<x≤6,x∈R}.
- At x=0: f(0)=2(0)−5=−5. Point: (0,−5) (This is an open circle as x>0).
- At x=1: f(1)=2(1)−5=−3. Point: (1,−3)
- At x=2: f(2)=2(2)−5=−1. Point: (2,−1)
- At x=3: f(3)=2(3)−5=1. Point: (3,1)
- At x=4: f(4)=2(4)−5=3. Point: (4,3)
- At x=5: f(5)=2(5)−5=5. Point: (5,5)
- At x=6: f(6)=2(6)−5=7. Point: (6,7) (This is a closed circle as x≤6).
3. Graph of f−1(x)=21x+25
The domain for f−1(x) is {x:−5<x≤7,x∈R}.
- At x=−5: f−1(−5)=21(−5)+25=−25+25=0. Point: (−5,0) (This is an open circle as x>−5).
- At x=−4: f−1(−4)=21(−4)+25=−2+2.5=0.5. Point: (−4,0.5)
- At x=−3: f−1(−3)=21(−3)+25=−1.5+2.5=1. Point: (−3,1)
- At x=−2: f−1(−2)=21(−2)+25=−1+2.5=1.5. Point: (−2,1.5)
- At x=−1: f−1(−1)=21(−1)+25=−0.5+2.5=2. Point: (−1,2)
- At x=0: f−1(0)=21(0)+25=2.5. Point: (0,2.5)
- At x=1: f−1(1)=21(1)+25=0.5+2.5=3. Point: (1,3)
- At x=2: f−1(2)=21(2)+25=1+2.5=3.5. Point: (2,3.5)
- At x=3: f−1(3)=21(3)+25=1.5+2.5=4. Point: (3,4)
- At x=4: f−1(4)=21(4)+25=2+2.5=4.5. Point: (4,4.5)
- At x=5: f−1(5)=21(5)+25=2.5+2.5=5. Point: (5,5)
- At x=6: f−1(6)=21(6)+25=3+2.5=5.5. Point: (6,5.5)
- At x=7: f−1(7)=21(7)+25=3.5+2.5=6. Point: (7,6) (This is a closed circle as x≤7).
Use these points to draw your graph accurately, remembering to use open circles for points that are not included in the domain/range and closed circles for points that are included.
3 done, 2 left today. You're making progress.