2cos(6y)+11cos(6y)sin(3y) i'm stuck somewhere in the middle... not because I can't solve it... my calculator won't respond... please complete it for me.

cos(6y)=0 or 2+11sin(3y)=0

Question

2cos(6y)+11cos(6y)sin(3y)        i'm stuck somewhere in the middle... not because I can't solve it... my calculator won't respond... please complete it for me.

cos(6y)=0 or 2+11sin(3y)=0  <=that's where i'm stuck

sasogeek · Answer

please solve in radians

sasogeek · Answer

radians... please...

sasogeek · Answer

my calculator won't respond so please do all the work :) thank you

lalaly · Answer

ok sorry cos inverse of 0 is pi/2

sasogeek · Answer

i have the solutions... i just need to know how to get there

ash2326 · Answer

$$\cos^{-1}  0=6y$$
or 6y=(2n+1)*pi/2
y=(2n+1)*pi/12

sasogeek · Answer

attachment

ash2326 · Answer

either this or
2+11 sin 3y=0
sin 3y =-2/11
$$3y=\sin^{-1} (-2/11 )$$
$$3y=-\sin^{-1}(2/11)$$
$$y=-(\sin^{-1} (2/11))/3$$

sasogeek · Answer

ok so i just opened up the page with the step-by-step solution... here's a snapshot

ash2326 · Answer

cos 6y=0
6y=(2n+1)pi/2
n= 0, +1 or -1 and so on
y=2npi/12+pi/12
y=n*pi/6+pi/12
y=pi/12 +pi*n/6

sasogeek · Answer

thanks btw, i'll go for a calc from a friend later today :) until then, thats all for now

ash2326 · Answer

saso geek in the answer ,the first solution misses some answers, you might need to check it again with your instructor:)