Saturday

December 20, 2014

December 20, 2014

Posted by **Sally** on Friday, December 26, 2008 at 3:45am.

sin x + (root 3)cos x = 0

- Maths -
**Damon**, Friday, December 26, 2008 at 9:10amWhenever you see sines and cosines and sqrt 3, draw a thirty, sixty ninety triangle.

the sin of the 60 degree angle is (sqrt 3)/2

the cosine of the 60 degree angle is 1/2

sqrt(3)/2 = (sqrt 3)(1/2)

Now the quadrants where the sine and cosine have opposite signs are quadrant 2 and quadrant four. So look in those two quadrants.

- Maths -
**Reiny**, Friday, December 26, 2008 at 12:17pmanother not necessarily better approach would be ...

sinx = -√3cosx

tanx = -√3

from the same triangle as Damon's we would get a "basic" angle of 60º or pi/3 radians

but the tan is negative in II or IV, so

x = pi - pi/3 or 2pi - pi/3

or x = 2pi/3 or 5pi/3

**Answer this Question**

**Related Questions**

math - Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the ...

maths - Choose the two options which are true for all values of x 1) cos (x) = ...

math - Prove that for all real values of a, b, t (theta): (a * cos t + b * sin t...

Trigonometry - find all x - Find all x such that 0 <= x <= pi/2 and sin^7 ...

Maths - 1) Simplification (trigonometric ratios of allied angles)? Simplify : i...

MATH - 1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL ...

math - use exact values of the sin,cos and tan of (pi/3) and (pi/6)(which I ...

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

tigonometry - expres the following as sums and differences of sines or cosines ...

Algebra II - Multiple Choice (theta) means the symbol 0 with the dash in it. 1.)...