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avatar+1124 

Hi friends....please a last question for today:

 

The sum goes like this:

 

22Cosx+SinxSinx

 

becomes

 

Sinx+Cosx2Sinx

 

I understand the sqrt of 2 going to the bottom, but what happenms to the denominator "2"??. Thanks a lot for your patience today. All the best. Untill next time!!.. smiley

 Mar 3, 2023
 #1
avatar+118696 
+1

 

22cosx+sinxsinx =2cosx+2sinx2sinx=2cosx+2sinx2÷sinx=2cosx+2sinx2sinx=2cosx+2sinx22sinx2=2cosx+2sinx22sinx=cosx+2sinx2sinx

 

 

BUT     If I put brackets into you question, this is what I get.

 

22[cosx+sinx]sinx=22[cosx+sinx]×1sinx=22[cosx+sinx]×1sinx×22=222[cosx+sinx]×1sinx=12[cosx+sinx]×1sinx=cosx+sinx2sinx

 

 

 

 

 

 

 

 

 

LaTex:

\frac{\frac{\sqrt2}{2}cos\;x\;+\;sin\;x}{sin\;x}\\~\\
=\frac{\frac{\sqrt2cosx+2sinx}{2}}{sinx}\\

=\frac{\sqrt2cosx+2sinx}{2}\div sinx\\
=\frac{\sqrt2cosx+2sinx}{2sinx}\\
=\frac{\frac{\sqrt2cosx+2sinx}{\sqrt2}}{\frac{2sinx}{\sqrt2}}\\
=\frac{\frac{\sqrt2cosx+2sinx}{\sqrt2}}{\sqrt2sinx}\\
=\frac{cosx+\sqrt2sinx}{\sqrt2sinx}\\

 Mar 4, 2023
 #2
avatar+1124 
0

Melody, once again, ..Thank you. So it's all about rasionalizing the numerator. I could do it like this:?

 

22(SinxCosx)Sinx

 

22(SinxCosx)Sinx22

 

which really means:

 

222(SinxCosx)2Sinx

 

which will then also produce the final correct answer?

 

By the way, the brackets were needed...I have forgotten to add them in the original sum...oopsie..sorry..sad

juriemagic  Mar 4, 2023
 #3
avatar+118696 
+1

Yes that is correct and it is easier than what I did.

There are many ways to go about this.

You forgot the plus sign though.   wink

Melody  Mar 4, 2023

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