Question

d(A,B)=10 if A=(-1,1),B=(5,y) find the value of y

Answer 1

Answer

Given A(2,−3)&B(10,y)  and  AB=10

Distance between two points    

(x  2 −x  1  )  2  +(y  2 −y  1  )  2

 

∴10=  (10−2)  2  +(y+3)  2

 

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Squaring both sides

⇒100=64+9+6y+y ^2

 

⇒y^2  +6y−27=0

⇒y(y+9)−3(y+9)=0

⇒y=−9,3