বৃত্তের সমীকরণ ও পোলার সমীকরণ সংক্রান্ত

The circle passing through the points (1,0)(-1,0) and touching the y-axis at (0,2)(0,2) also passes through the point:

হানি নাটস

Let (h,k)\left( h, k \right) be center of circle.
Circle touches the yy-axis.

\therefore Radius of circle =h= h

Equation of circle-

(xh)2+(yk)2=h2.....(1){\left( x - h \right)}^{2} + {\left( y - k \right)}^{2} = {h}^{2} ..... \left( 1 \right)
Since the circle passes through (0,2)\left( 0, 2 \right)

Therefore,

h2+(2k)2=h2{h}^{2} + {\left( 2 - k \right)}^{2} = {h}^{2}

(k2)2=0\Rightarrow {\left( k - 2 \right)}^{2} = 0

k=2\Rightarrow k = 2

Given that the circle also passes through (1,0)\left( -1, 0 \right),

Therefore,

(1h)2+22=h2{\left( -1 - h \right)}^{2} + {2}^{2} = {h}^{2}

h2+1+2h+4=h2{h}^{2} + 1 + 2h + 4 = {h}^{2}

h=52h = - \cfrac{5}{2}

Substituting the value of hh and kk in eqn(1){eq}^{n} \left( 1 \right), we get

(x+52)2+(y2)2=(52)2{\left( x + \cfrac{5}{2} \right)}^{2} + {\left( y - 2 \right)}^{2} = {\left( \cfrac{5}{2} \right)}^{2}

Now, we can find the point from which the circle passes.

As the point (4,0)\left( 4, 0 \right) satisfy the equation of circle.

Thus, the circle will also pass through the point (4,0)\left( -4, 0 \right).

Hence the correct answer is (D)(4,0)\left( D \right) \left( -4, 0 \right).

বৃত্তের সমীকরণ ও পোলার সমীকরণ সংক্রান্ত টপিকের ওপরে পরীক্ষা দাও