What values for q (0 < q < 2p) satisfy the equation? 2sqrt(2)sin q + 2 = 0
\(\bf \large 2\sqrt{2}sin(q)+2=0\ \ ;\ \ 0 < q < 2\pi\)
Can someone teach me how to solve this? I would like to be able to solve it on my own bu the text book is just not making sense today.
do the regular algebra by isolating sin(q) on one side of the equal sign....
\(\bf \large {2\sqrt{2}sin(q)+2=0; 0 < q < 2\pi\\ sin(q) = \frac{2}{2\sqrt{2}} = \frac{1}{\sqrt{2}} = \frac{\sqrt{2}}{2}}\)
that should be negative on the right side... ie, \(\frac{-2}{2\sqrt2} \)
wait! so the first step is to divide by \[2\sqrt{2}\] to move it to the right??
actually, yes, should be -2 :/
no... move the lone "2" first by subtractig...
ok i see that which is where the nominator comes from.
\(\bf \large 2\sqrt{2}sin(q)+2=0; 0 < q < 2\pi\\ \large sin(q) = -\frac{2}{2\sqrt{2}} = -\frac{1}{\sqrt{2}} = -\frac{\sqrt{2}}{2}\)
yep...
how did the \[\sqrt{2}\] get on top of the fraction?
then for that, just check your Unit Circle for the angles between 0 and \(\bf \large \pi\) that have that value with a NEGATIVE sign
it gets there by "simplifying" the rational, so-called
\(\bf \large { 2\sqrt{2}sin(q)+2=0; 0 < q < 2\pi\\ sin(q) = -\frac{2}{2\sqrt{2}} = -\frac{1}{\sqrt{2}} \times \frac{\sqrt{2}}{\sqrt{2}} = -\frac{\sqrt{2}}{2} } \)
Alright, none of my choices are negative though.
well, check your Unit Circle for such values
between 0 and \(\bf \large \pi \) there'd be 2 angles with that sine value
I'm sorry I have got to sound dumb but I don't know what a unit circle is.
All of my options have two fractions. I am not sure how to paste the pictures to here.
many Unit Circles online, you'd need one :)
Thank you! Now you said between 0 and pi there would be angles with the sign value.
yes, and at those angles, is where the equation holds, that is \(\bf 2\sqrt{2}sin(q)+2=0\)
So my answer would be \[2\sqrt{2}\]
oops i meant to flip those
\[\sqrt{2}/2\]
well, "q" is an angle unit, so the values where \(\bf \large sin(q) = -\frac{\sqrt{2}}{2}\) is what "q" equals to, there are 2 angles, one in the 3rd quadrant and another in the 4th quadrant
ok so one of my answers should be \[7\pi/4\]
and the other will be found at 135deg \[\pi/4\]
!I see it. Thank you so much I actually understand how to do these now!!!
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