Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202430 JanuaryMorning Shift
Exam
JEE Main
Year
2024
Date
30 January
Shift
Morning Shift
Subject
Mathematics
Chapter
Circle

JEE Main 2024 · 30 January · Morning Shift · Mathematics · Circle

If the circles ( x + 1 ) ^ 2 + ( y + 2 ) ^ 2 = r ^ 2 and x ^ 2 + y...

If the circles (x+1)2+(y+2)2=r2( x + 1{)}^{2} + ( y + 2{)}^{2} = {r}^{2} and x2+y2−4x−4y+4=0{x}^{2} + {y}^{2} - 4x - 4y + 4 = 0 intersect at exactly two distinct points, then

Options

  1. A5<r<95 < r < 9
  2. B0<r<70 < r < 7
  3. C3<r<73 < r < 7
  4. D12<r<7\dfrac{1}{2} < r < 7

Correct answer

C. 3<r<73 < r < 7

Step-by-step solution

Given,

S1≡(x+1)2+(y+2)2=r2and{S}_{1} ≡ {\left(x + 1\right)}^{2} + {\left(y + 2\right)}^{2} = {r}^{2} and{S}_{2} ≡ {x}^{2} + {y}^{2} - 4x - 4y + 4 = 0 or {S}_{2} ≡ {\left(x - 2\right)}^{2} + {\left(y - 2\right)}^{2} = {2}^{2}</p><p>Now,iftwocirclesintersectattwodistinctpoints then ∣r1−r2∣<C1C2<r1+r2</p><p>Now, if two circles intersect at two distinct points then \left|{r}_{1} - {r}_{2}\right| < {C}_{1}{C}_{2} < {r}_{1} + {r}_{2}.

⇒∣r−2∣<32+42<r+2⇒ \left|r - 2\right| < \sqrt{{3}^{2} + {4}^{2}} < r + 2

⇒∣r−2∣<5<r+2⇒ \left|r - 2\right| < 5 < r + 2

⇒∣r−2∣<5andr+2>5⇒ \left|r - 2\right| < 5\text{and}r + 2 > 5

⇒−5<r−2<5andr>3⇒ - 5 < r - 2 < 5\text{and}r > 3

⇒−3<r<7andr>3⇒ - 3 < r < 7\text{and}r > 3

⇒3<r<7⇒ 3 < r < 7

Practice Circle on Quantrex Academy →

More from Circle

Match each entry in List-I to the correct entry in List-II and choose the correct option.… JEE Advanced 2026Consider the circle C: x^2+y^2-6x-8y-11=0 . Let a variable chord AB of the circle C… JEE Main 2026Let C be a circle having centre in the first quadrant and touching the x -axis at a… JEE Main 2026Let the line x - y = 4 intersect the circle C: (x-4)^2 + (y+3)^2 = 9 at the points Q and… JEE Main 2026Let the centre of the circle x^2 + y^2 + 2gx + 2fy + 25 = 0 be in the first quadrant and… JEE Main 2026Let P be a moving point on the circle x^2 + y^2 - 6x - 8y + 21 = 0 . Then, the maximum… JEE Main 2026Suppose that two chords, drawn from the point (1, 2) on the circle x^2 + y^2 + x - 3y = 0… JEE Main 2026Let a circle pass through the origin and its centre be the point of intersection of two… JEE Main 2026Let a circle C have its centre in the first quadrant, intersect the coordinate axes at… JEE Main 2026Let the circle x^ 2 +y^ 2 =4 intersect x -axis at the points A(a, 0), a>0 and B(b, 0) .… JEE Main 2026Let y=x be the equation of a chord of the circle C_ 1 (in the closed half-plane x ≥ 0 )… JEE Main 2026Let S=\ z ∈ ℂ:|(z-6 i)/(z-2 i)|=1. and .|(z-8+2 i)/(z+2 i)|=(3)/(5)\ . Then ∑_ z ∈ ~s… JEE Main 2026Let a circle of radius 4 pass through the origin O, the points A(- 3 a, 0) and B(0,- 2 b)… JEE Main 2026If the points of intersection of the ellipses x^ 2 +2 y^ 2 -6 x-12 y+23=0 and 4 x^ 2 +2… JEE Main 2026Let the set of all values of r , for which the circles (x+1)^ 2 +(y+4)^ 2 =r^ 2 and x^ 2… JEE Main 2026If P is a point on the circle x^ 2 +y^ 2 =4, Q is a point on the straight line 5 x+y+2=0… JEE Main 2026 Full Circle list Circle JEE Maths PYQsJEE Mathematics PYQs All JEE Main PYQs