# SOLUTION: These kind of problems are really confusing to me... simplify 5cis115degrees * 4cis10degrees I'm not even sure where to start. thank you much!

Algebra ->  Algebra  -> Trigonometry-basics -> SOLUTION: These kind of problems are really confusing to me... simplify 5cis115degrees * 4cis10degrees I'm not even sure where to start. thank you much!      Log On

 Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations! Ad: Algebra Solved!™: algebra software solves algebra homework problems with step-by-step help!

 Algebra: Trigonometry Solvers Lessons Answers archive Quiz In Depth

 Question 173152: These kind of problems are really confusing to me... simplify 5cis115degrees * 4cis10degrees I'm not even sure where to start. thank you much!Answer by jim_thompson5910(28503)   (Show Source): You can put this solution on YOUR website!In general cis(x) = cos(x)+i*sin(x) where . The "cis" is just a faster way of writing the right side of the equation So cis(115) = cos(115)+i*sin(115) Use a calculator to get: cos(115) = -0.42262 and sin(115) = 0.90631 So this means that cis(115) = -0.42262 + 0.90631*i Furthermore, 5*cis(115) = 5*(-0.42262 + 0.90631*i)=-2.1131+4.53155*i I hope I got you going in the right direction to evaluate 4*cis(10) If not, then either let me know or repost the problem