Wednesday

August 20, 2014

August 20, 2014

Posted by **anon** on Monday, October 21, 2013 at 5:36pm.

- math -
**Reiny**, Monday, October 21, 2013 at 5:43pm1 - 2sin^2 x - sinx = 0

2sin^2 x + sinx - 1 = 0

(2sinx - 1)(sinx + 1) = 0

sinx = 1/2 or sinx = -1

in degrees, x = 30° , 150° , 270°

in radians, x = π/5 , 5π/6 , 3π/2

- math -
**anon**, Monday, October 21, 2013 at 5:46pmThanks. I was wondering, why is it "+ sin x" in the second step?

- math -
**anon**, Monday, October 21, 2013 at 5:47pmdo you just change all the signs of the terms? if so, why is this necessary?

- math -
**Reiny**, Monday, October 21, 2013 at 5:51pmI multiplied each term by -1

(notice all the signs have switched)

I like my quadratics to start with a positive coefficient, although that would not be necessary.

It just makes it easier to factor.

- math -
**anon**, Monday, October 21, 2013 at 5:55pmok thank you.

**Related Questions**

math - the problem is 2cos^2x + sinx-1=0 the directions are to "use an identity ...

Trig Help - Prove the following: [1+sinx]/[1+cscx]=tanx/secx =[1+sinx]/[1+1/sinx...

math - solve each equation for 0=/<x=/<2pi sin^2x + 5sinx + 6 = 0? how do ...

Trig........ - I need to prove that the following is true. Thanks (cosx / 1-sinx...

trigonometry - can i use factoring to simplify this trig identity? the problem ...

Math - Trig - Double Angles - Prove: sin2x / 1 - cos2x = cotx My Attempt: LS: = ...

Trig - Verify the identity: tanx(cos2x) = sin2x - tanx Left Side = (sinx/cosx)(...

Math (Trig) a.s.a.p, thanks! - verify the identities: 1.) 2tanx-(1+tanx)^2 = -...

Mathematics - Trigonometric Identities - Prove: (tanx)(sinx) / (tanx) + (sinx...

Math - prove identity Sin2x - sinx/cosx + cos2x= sinx/cosx + 1