Posted by **please help now** on Sunday, February 26, 2012 at 12:58pm.

Solve for x if sin2x=cos(x+60 and x€ [-90,180].show all work details

- trig -
**drwls**, Sunday, February 26, 2012 at 1:40pm
What does x€ [-90,180] mean?

The domain limits of x?

You seem to have omitted a parenth after x+60

cos(x+60) = sin(90-x-60)

= sin (30-x)

sin2x = sin(30-x)

Therefore 2x = 30 -x

x = 10 degrees is one solution

See if you can find others. Note that sin2x = sin(180 -2x); that will lead to another solution.

- trig -
**please help now**, Monday, February 27, 2012 at 12:49pm
Yes it mean domaim limit of x that guied u when plot the graph

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