Wednesday

April 16, 2014

April 16, 2014

Posted by **Abbey** on Wednesday, March 17, 2010 at 12:18am.

sin[x + pi/4] + sin[x-pi/4] = -1

sinx cospi/4 + cosxsin pi/4 + sinx cos pi/4 - cosx sin pi/4 = -1

2 sin x cos pi/4 =-1

cos pi/4 = sqr2/2

2sin^x(sqrt2/2) = -1

sin x = -sqrt2

x = 7pi/4 and 5pi/4

Am I correct?

- Math(Please help) -
**Damon**, Wednesday, March 17, 2010 at 6:51am2sin^x(sqrt2/2) = -1

sin x = -1/sqrt2 = - sqrt 2 /2

x = pi + pi/4 = 5 pi/4

x = 2 pi - pi/4 = 7 pi /4

so I agree with you but you seem to have a typo

**Related Questions**

Math(Please help) - 1)tan Q = -3/4 Find cosQ -3^2 + 4^2 = x^2 9+16 = sqrt 25 = 5...

math - Eliminate the parameter (What does that mean?) and write a rectangular ...

Math - use the sum and difference identities to find the cosine angle cos pi/9 ...

trig - prove the following trig identity: a) sin(pi/6 + x) + sin (pi/3 + x) + ...

Pre-Cal - Find the 5 roots of x^5+1=0 in polar and Cartesian form. (x^5 means x ...

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

trig - Give exact answers Sin(11pi/8) so this is sin(pi/4+pi/3) sin(pi/4)*cos(pi...

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

d/dx - d/dx( ln |sin(pi/x)| ) = ? Thanks. If those are absolute value signs, the...

maths - hey, i would really appreciate some help solving for x when: sin2x=cosx ...