### Home > CALC > Chapter 12 > Lesson 12.1.2 > Problem 12-27

12-27.

**Multiple Choice:**At the points where the limaςon*r*= 5 − 4 cos*θ*has a horizontal tangent, the following equation is true: Homework Help ✎sin

*θ*= 05 sin

*θ*= 4 sin 2*θ*5 sin

*θ*= 2 sin 2*θ*5 cos

*θ*= 2 cos 2*θ*5 cos

*θ*= 4 cos 2*θ*

This is when *dy*/*dθ* = 0.

You will need to use a double angle identity to rewrite your *y* = equation or your final answer.