The graph of a limacon curve is given. Without using your graphing calculator, determine which equation is correct for the graph. [-5, 5] by [-5, 5]. a. r= 2-2 sinθ b. r= 3-2 sinθc. r= 2+2 sinθd. r= 1-3 sinθ
Accepted Solution
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Answer:The equation of the limacon is r = 2 - 2 sinФ ⇒ answer (a)Step-by-step explanation:* Lets study the limacon curve- Equations of the form:# r = a + b sin θ# r = a – b sin θ# r = a + b cos θ# r = a – b cos θ All will produce limacons. * Lets examine what happens for various values of a and b.- When the value of a is less than the value of b, the graph is a limacon with and inner loop. ⇒ figure (1)- When the value of a is greater than the value of b, the graph is a dimpled limacon. ⇒ figure (2)- When the value of a is greater than or equal to the value of 2b, the graph is a convex limacon. ⇒ figure (3)- When the value of a equals the value of b, the graph is a special case of the limacon. It is called a cardioid. ⇒ figure (4)* Notice that, in each of the graphs of the liamsons, changing from sine to cosine does not affect the shape of the graph just its orientation. - Equations using sine will be symmetric to the vertical axis- Equations using cosine are symmetric to the horizontal axis.* The sign of b will also affect their orientation.- The large of the graph under the x-axis or left to the y-axis b is -ve- The large of the graph over the x-axis or right to the y-axis b is +ve* lets look to the graph∵ The graph is symmetric to the y- axis∵ The graph is a cardioid∴ a = b∵ The large part of the graph under the x-axis∴ b is -ve∴ The answer is r = 2 - 2 sinФ* The equation of the limacon is r = 2 - 2 sinФ