Tuesday

September 23, 2014

September 23, 2014

Posted by **Marie** on Friday, August 3, 2012 at 3:50pm.

- Trigonometry -
**MathMate**, Friday, August 3, 2012 at 6:06pmsin(2x)=2sin(x)cos(x)

so

sin(2x)+sin(x)=0

=>

2sin(x)cos(x)+sin(x)=0

sin(x)[2cos(x)+1]=0

sin(x)=0 or cos(x)=-1/2

sin(x)=0 => x=0, x=π for 0≤x<2π

cos(x)=-1/2 => x=2π/3 or x=4π/3

Combining, the solution set

S={0,2π/3,π 4π/3}

Add x=2π if the question actually asked for

0≤x**≤2π**

**Answer this Question**

**Related Questions**

Trigonometry - 4. Find the exact value for sin(x+y) if sinx=-4/5 and cos y = 15/...

i lied. very quick calc problem. - f(x) = abs(sin(x)), -pi less than or equal to...

Precalculs - I have no idea how to do these type of problems. -------Problem...

trigonometry - Solve the equation 6 cos x^2+sin x=4 if 0 is less than or equal ...

Trigonometry - Thank you STEVE!!!!! Suppose that Cos (theta) = 1/square root 2 ...

math - Find intervals on which the following functions are increasing and ...

Math/Trig - Solve: sin x - 2sin x cos x = 0 for 0 is less than or equal to x is ...

Trigonometry - Solve for the following equation to the nearest degree if needed ...

algebra - Suggest a cubic that would best approximate a sine wave (f(x) = sin(x...

precalculus - Solve sin(x) = 0.64 on 0 less than or equal to x less than 2pi ...