14.3.2. Cardioid
The polar equation for a cardioid can be written as r = a + a cos θ or r = a + a sin θ. Enter one equation per line. If the equation is written as "r =" you do not need to type "r =" again.
Examples
Sketch the graph of the equations below and hit enter after each one.
1. r = 4 – 4 cos θ
2. r = 6 – 6 cos θ
3. r = 5 + 5 sin θ
4. r = 1 + sin θ
Calculator solutions
Enter each of the following. Type θ by tapping the x variable key five times.
1) 4 – 4 cos θ
2) 6 – 6 cos θ
3) 5 + 5 sin θ
4) 1 + sin θ
Examples
Sketch the graph of the equations below and hit enter after each one.
1. r = 4 – 4 cos θ
2. r = 6 – 6 cos θ
3. r = 5 + 5 sin θ
4. r = 1 + sin θ
Calculator solutions
Enter each of the following. Type θ by tapping the x variable key five times.
1) 4 – 4 cos θ
2) 6 – 6 cos θ
3) 5 + 5 sin θ
4) 1 + sin θ
To look at each graph individually, enter one equation per workspace. Adjust the r-axis fixed scale to resize the graph. Set it to a smaller value (e.g. 1, 0.5, 0.3) to enlarge the scale or set it to a higher value (e.g. 3, 5) to reduce it.
