Solve the following equations for 0<x<360 ?

**moesizlak** · January 30th 2011, 01:05 PM

v) sin^2x=1-cosx
vi)sin^2x=1
vii)1-cos^2x=2sin x
viii) sin^2 x=2cos^2 x
ix) 2sin^2 x=3cos x
x) 3tan^2x-10tan x +3=0
thanks in advance really stuck !

**chisigma** · January 30th 2011, 01:19 PM

v) $\sin^{2} x = 1-\cos x \implies 1-\cos^{2} x = 1-cos x \implies 1+\cos x = 1 \implies \cos x =0$ ...

Kind regards

$\chi$ $\sigma$

**skeeter** · January 30th 2011, 03:19 PM

Originally Posted by moesizlak

v) sin^2x=1-cosx

1 - cos^2x = 1 - cosx

cosx - cos^2x = 0

cosx(1 - cosx) = 0

cosx = 0 , cosx = 1

x = 90 , 270 ... x = 0 , 360

same idea with the rest. show us something.

**Prove It** · January 30th 2011, 04:13 PM

Originally Posted by chisigma

v) $\sin^{2} x = 1-\cos x \implies 1-\cos^{2} x = 1-cos x \implies 1+\cos x = 1 \implies \cos x =0$ ...

Kind regards

$\chi$ $\sigma$

Though shalt not divide by 0...

**mr fantastic** · January 31st 2011, 12:33 AM

Originally Posted by moesizlak

v) sin^2x=1-cosx
vi)sin^2x=1
vii)1-cos^2x=2sin x
viii) sin^2 x=2cos^2 x
ix) 2sin^2 x=3cos x
x) 3tan^2x-10tan x +3=0
thanks in advance really stuck !

Please don't post more than two questions in a thread. Otherwise the thread can get convoluted and difficult to follow. See rule #8: http://www.mathhelpforum.com/math-he...ng-151418.html.

Thread closed.

Thread: Solve the following equations for 0<x<360 ?