# Solve the following equations for 0<x<360 ?

• Jan 30th 2011, 01:05 PM
moesizlak
Solve the following equations for 0<x<360 ?
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 !
• Jan 30th 2011, 01:19 PM
chisigma
v) $\displaystyle \sin^{2} x = 1-\cos x \implies 1-\cos^{2} x = 1-cos x \implies 1+\cos x = 1 \implies \cos x =0$...

Kind regards

$\displaystyle \chi$ $\displaystyle \sigma$
• Jan 30th 2011, 03:19 PM
skeeter
Quote:

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.
• Jan 30th 2011, 04:13 PM
Prove It
Quote:

Originally Posted by chisigma
v) $\displaystyle \sin^{2} x = 1-\cos x \implies 1-\cos^{2} x = 1-cos x \implies 1+\cos x = 1 \implies \cos x =0$...

Kind regards

$\displaystyle \chi$ $\displaystyle \sigma$

Though shalt not divide by 0...
• Jan 31st 2011, 12:33 AM
mr fantastic
Quote:

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 !

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