Find the point on the graph of y Squareroot x2 1 that is c
Solution
point on graph y=(x2-1) is (x,y)
distance detween point on graph (x,y) and (0,1) is d=[x2+(y-1)2]
d=[x2+((x2-1) -1)2]
d=[x2+(x2-1) +1-2(x2-1)]
d=[2x2-2(x2-1)]
(x,y) is closest point to (0,1) when distance is minimum
distance is minimum when f(x)=2x2-2(x2-1) is minimum
f(x) is ,minimum when f \'(x)=0
f \'(x)=4x -(2*2x/2(x2-1)) =0
f \'(x)=4x -(2x/(x2-1)) =0
2x[2-(1/(x2-1))]=0
x=0 ,2-(1/(x2-1))=0
2= 1/(x2-1)
=>2(x2-1) =1
=>4(x2-1)=1
=>4x2-4=1
=>4x2=5
=>x=(5)/2 .x=-(5)/2
x=0 ,=>y is undefined
x=-(5)/2 => y=((-(5)/2)2-1) =1/2
x=(5)/2 => y=(((5)/2)2-1) =1/2
x=-(5)/2,d=[2x2-2(x2-1)]
d=[2(-(5)/2)2-2((-(5)/2)2-1)] =(3/2)
x=(5)/2,d=[2x2-2(x2-1)]
d=[2((5)/2)2-2(((5)/2)2-1)] =(3/2)
coordinates of closest points are (-(5)/2 ,1/2) ,((5)/2 ,1/2)
coordinates of closest points are (-1.12 ,0.5) ,(1.12 ,0.5)
