Please solve the following question from trigonometry:
Attachments:
HellostudyFriend:
nothing as such is given
is there a figure?
no bro
nothing is there
where is the qn from?
I don't know. Somebody had sent it to me on WhatsApp.
which grade is this for?
It is for 11 th class.
oh ok ,i assumed it was for 10th, if its for 11th then use the formula cos(A+B) = cosAcosB - sinAsinB & sin(A+B) = sinAcosB + sinBcosA
Ok. Thank you.
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Answer:this is how u do it ...i did it by calculating cos(α+β) first
a2+b2=sin2α+sin2β+2sinαsinβ+cos2α+cos2β+2cosαcosβ
a2+b2=(sin2α+cos2α)+(sin2β+cos2β)+2(cosαcosβ+sinαsinβ)
a2+b2=2(1+cos(α−β))
a2+b22=(1+cos(α−β))
b2−a2=(cos2α−sin2α)+(cos2β−sin2β)+2cosαcosβ−2sinαsinβ
b2−a2=(cos2α−(1−cos2α))+(1−sin2β)−sin2β))+2(cosαcosβ−sinαsinβ)
b2−a2=2(cos2α−sin2β+cos(α+β))
b2−a2=2(cos(α+β)cos(α−β)+cos(α+β))
b2−a22=cos(α+β){cos(α−β)+1}
b2−a22=cos(α+β){b2+a22}
cos(α+β)=a2+b2a2−b2
Then just calculate sin(α+β) by 1−cos2(α+β)
Step-by-step explanation:
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