Wednesday
April 16, 2014

Homework Help: trig

Posted by Devon on Monday, April 16, 2007 at 9:14pm.

find the exact solutions

2cos^2x+3sinx=0

the way it stands, that is a "nasty" question.
Are you sure the second term isn't 2sin(2x) ?

no, its as i wrote it.

then it's got me stymied, I must be missing something rather obvious, sorry!



thanks for trying!

2cos^2x+3sinx=0
2-2sin^2x + 3 sinx=0
sin^2 x - 3/2 sin x - 1=0

quadratic equation..

sinx= (3/2 +-sqrt(9/4 +4) /2
sinx= 3/4 +- 5/4

sin x= -1/2 works.

check me.

thank you!

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