Wednesday

April 16, 2014

April 16, 2014

Posted by **Cody** on Friday, February 18, 2011 at 5:00pm.

- trig -
**Reiny**, Friday, February 18, 2011 at 5:22pmthen cosx = -1/√3

x must be in II or III

in II:

sinx = √2/√3

sin 2x = 2sinxcosx = 2(√2/√3)(-1/√3) = -2√2/3

in III:

sinx = -√2/√3

sin 2x = +2√2/3

**Related Questions**

Trig - If secx = 8 and -pi/2 < x < 0, find the exact value of sin2x Use ...

Trig functions and such - 1)Find the exact value of cot(-315) A)1 B)square root ...

Trig - Why is the arctan of - square root of 3 equal a negative value (-pi/3) ...

Math - i^6 = (i^2)^3 = (-1)^3 = -1 The square, not the square root of -1 is 1...

Trig - I'm confused on how to determine what the end result angles are for a ...

Trig - 1. Establish the identity: sin(theta+3pi/2)=-cos(theta) 2. Find the exact...

Algebra - I am supposed to "write each expression with a rational denominator" 1...

trig - what is the exact value of cos(x+y) if tan=x sqare root 3 over 3 and sin ...

math-trig - Use the double angle identities to find sin2x if sinx= 1/square of ...

Algebra - Use the quadratic formula to solve the equation. Give exact answers: ...