maths trig question (1 Viewer)

[jessica_layden]

hey i was just wondering if anyone can help me with these 2 trig questions


1) find the value of x if sin(20+2x) = cos(x+10)

and

2) solve 4 sinxcosx = root 3 ( for -180 smaller than or equal to x smaller than or equal to 180)

thanks

 

[~*HSC 4 life*~]

Originally posted by jessica_layden

2) solve 4 sinxcosx = root 3 ( for -180 smaller than or equal to x smaller than or equal to 180)

thanks

use t-results

 

[Giant Lobster]

nah convert it into sin2x
and for 1) convert the cos into a sin, and equate
heh ask in the math forums

 

[~*HSC 4 life*~]

ah yes sin 2x would be the way to go...

crap i need revision BAD!

 

[Heinz]

For 1 I wouldve substituted x+10 for u to get sin2u = cosu and solve that.