Find the minimum value of ..

find minimum and maximum value of x^2+y^2

if (x-3)^2+(y-4)^2=10^2

9 Answers

1
Rohan Ghosh ·

put x-3 =10cosθ
and y-4=10sinθ

as then it becomes a parametric form of circle as given in equation
parameter =θ
hence x+y =7+10(sinθ+cosθ)

hence ans =
min =7-10√2
max=7+10√2

1
krish1092 ·

@rohan2007
Can you please explain,on what basis,you substitute x-3=10sinθ and
y-3=10cosθ

1
Rohan Ghosh ·

it follows form the parametric equation of the circle

(x-a)2+(y-b)2=r2

each point can be expressed of the form

(a+rcosθ,b+rsinθ)

hence above i have written x and y in that form..

1
ith_power ·

it is due to parametric form of any st. line passing through center 3,4 and having a slope tanθ cutting circle at x,y. find distance of x,y from origin.

1
Swetha Kaushik ·

thanks rohan :)

1
E=mc^2 darkangel ·

hey rohan we are asked to find the value of x^2 + y^2 not x+y

the answer is 169 and 25

there is a simple logic

we hve to find the distance of the points nearest and closest to origin
so find the equation of the diameter passing through origin and find the pts. of intersection

1
Swetha Kaushik ·

hence x+y =7+10(sinθ+cosθ)

here rohan made a mistake

it was x^2+y^2

i realised now only..

btw.. good solution coolspirits :) that was awesome :)

1
Rohan Ghosh ·

swetha did you change the ques now

as i saw it find the min. and max value of x+y

62
Lokesh Verma ·

No rohan if she did.. there wud have been a small thing written under her post : "Last edited on:......."

neways dont worry ur approach was right.. :)

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