Posted by **MATHS QUESTION!!!!!!!!!!!!!!!!!!!!!!!!!!** on Sunday, December 6, 2009 at 2:00pm.

solve algebriaclly the equation y=2sin2x+1 for 0<_x_<180. when solved find the x coordinates of the roots.

- PLEASE ANSWER MATHS!!! -
**Reiny**, Sunday, December 6, 2009 at 2:18pm
I am assuming you are trying to solve

2sin2x+1 = 0

sin 2x = -1/2

(angle in standard position is 30º)

the sine is negative in quadrants III and IV

so x = 180+30 = 210

or x = 360-x30 = 330

Btw, don't shout!

- Shouting! -
**Writeacher**, Sunday, December 6, 2009 at 2:25pm
When you type in all-caps, two things happen:

**it's harder to read, and

**it's the online equivalent to SHOUTING (considered rude behavior).

Please just type in regular mode, not with the Caps Lock feature turned on. Thanks.

- Correction -
**Reiny**, Sunday, December 6, 2009 at 2:34pm
my last couple of lines should have been

so 2x = 180+30 = 210

or 2x = 360-x30 = 330

so x = 105 or x = 165

since the period of sin 2x is 180º

two other solutions are 285º and 345º

check: 2sin(2x345) + 1 = 0

## Answer this Question

## Related Questions

- algebra - 1)Solve by factoring:5x^2=4-19x answer=-4,1/5 2)Which quadratic ...
- equation complex number - z^4 + 81 = 0 (solve) change it to polar, then take ...
- MATHEMATICS - what is the exact value of 1-2sin(15degrees)? also 2(sin2x)=2sinx ...
- maths - find the roots of the equation X(square)+7x equal to 0.(b)write down the...
- Algebra - 1)Solve by factoring:5x^2=4-19x answer=-4,1/5 2)Which quadratic ...
- maths - the mid-point of the line FG is (6,10). if the coordinates of G is (8,14...
- Math - I can't remember how you find the roots of quadratic equations other than...
- Algebra - This will be a multiple post thing so please bear with me. If my ...
- Algebra 2 - How do I solve polynomial equation by finding all complex roots? The...
- Algebra2 - Find the polynomials roots to each of the following problems: #1) x^2...

More Related Questions