Thursday

January 29, 2015

January 29, 2015

Posted by **Trig** on Thursday, July 4, 2013 at 4:14pm.

sin 2x + sin x = 0

- trig -
**Damon**, Thursday, July 4, 2013 at 5:25pmsin 2 x = 2 sin x cos x

2 sin x cos x + sin x = 0

sin x (2 cos x + 1) = 0

so

x = 0 is a solution and x = 180 is a solution

then

cos x = -1/2

that is at x = 120 and x = 240

- trig -
**Reiny**, Thursday, July 4, 2013 at 9:45pmWe should also include 360° , (from sinx = 0)

**Answer this Question**

**Related Questions**

Pre-Calculus - cos^2(x) + sin(x) = 1 - Find all solutions in the interval [0, ...

Math Trig - Find all solutions on the interval [0,2pi] for the following: 2sin^2...

trig - Solve cos x-1 = sin^2 x Find all solutions on the interval [0,2pi) a. x=...

trig - I need to find all solutions of the given equations for the indicated ...

trig - Find the exact solutions of the equation in the interval [0,2pi). sin(x/2...

Math - Can I please get some help on these questions: 1. How many solutions does...

math - find all solutions in the interval [0,2 pi) sin(x+(3.14/3) + sin(x- 3.14/...

Calculus - I need to find the exact solutions on the interval [0,2pi) for: 2sin^...

TRIG! - Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6...

Trigonometry - Find all solutions of the equation in the interval [0,2pi] ...