2 Let pxy be a point on the graph of yx3 Express the distanc
2. Let p=(x,y) be a point on the graph of y=x^3. Express the distance d from P to the point (2, 0) as function of x. What is d if x=-1?
Solution
Y = x^3
Point ( 2, 0)
Distnace between any point on Y = x^3 be (x, y)
So, distnace between (x, y) and ( 2, 0) is given as:
d = sqrt( (x-2)^2 +( y-0)^3 )
= sqrt( ( x-2)^2 +y^2 )
Now we know y = x^3 ----> y^3 = x^6
So, d = sqrt( (x-2)^3 +x^6)
So we have distance in terms of x :
d = sqrt( (x-2)^3 +x^6)
if d=1
So, 1 = d = sqrt( (x-2)^3 +x^6)
if x=-1 ; d= sqrt( (-1-2)^2 +1) = sqrt( 10)
