Question 941246
<pre>

{{{y}}}{{{""=""}}}{{{D+A*cos(B^""(theta+C))}}}
{{{y}}}{{{""=""}}}{{{D+A*sin(B^""(theta+C))}}}

To find the 5 most important points,
1. Calculate 90°/B.
2. Begin with -C
3. Add what you got for step 1, 4 times to get the x-coordinants.
4. Substitute these in the original to get the y-coordinates.

{{{y}}}{{{""=""}}}{{{3+4cos(5^""(theta-"10°"))}}}

To find the 5 most important points,
1. Calculate 90°/5 = 18°.
2. Begin with -(-10°) = 10°
3. Add 18° 4 times to get the x-coordinants
   10°, 28°, 46°, 64°, 82°
4. Substitute in the original equation to get the y-values
   7,3,-1,7,3

Plot the 5 points (10°,7), (28°,3), (46°,-1), (64°,3), (82°,7)

{{{drawing(400,200,-20,100,-2,8,

graph(400,200,-20,100,-2,8,

3+4cos(5(x-10)*pi/180)*

(sqrt(x-10)/sqrt(x-10))*

(sqrt(82-x)/sqrt(82-x))


) )}}}

[The computer labels the points on the x-axis above in a crazy way,
You should label your x-axis with the x-coordinates of the 5 points.]

Edwin</pre>