Answer:
Here is a link to help you. This is a very great video that will help you understand proportionalities .
Step-by-step explanation:
https://www.khanacademy.org/math/cc-seventh-grade-math/cc-7th-ratio-proportion/7th-constant-of-proportionality/v/constant-of-proportionality-from-equation
15) factor out cos: cos(x)(sin(x)+1)=0
Now this is true when either cos(x)=0 (x=pi/2 and 3pi/2)
Or when sin(x)=-1 (x=3pi/2)
So it's solutions are pi/2 and 3pi/2
In the attachment this is how i did it! ~Best of Luck~
