9
7
4
3
Correct answer is C
Given the equation of the circle x2+y2−8x−2y+1=0.
The equation of a circle is given as (x−a)2+(y−b)2=r2
Expanding, we have x2−2ax+a2+y2−2by+b2=r2≡x2−2ax+y2−2by=r2−a2−b2
Comparing the RHS of the equation above with the equation rewritten as x2+y2−8x−2y=−1, we have
−2a=−8;−2b=−2⟹a=4,b=1
∴
r = \sqrt{16} = 4
Given that \alpha and \beta are the roots of an equation such that \alpha + \beta = 3 an...
The marks scored by 4 students in Mathematics and Physics are ranked as shown in the table below ...
Find the direction cosines of the vector 4i - 3j....
The roots of the quadratic equation 2x^{2} - 5x + m = 0 are \alpha and \beta, where m is...
Given that \frac{3x + 4}{(x - 2)(x + 3)}≡\frac{P}{x + 3}+\frac{Q}{x - 2},find the value of...
If P = \begin{vmatrix} 1 & 1 \\ 2 & 1 \end{vmatrix}, find (P^{2} + P)....
Find the gradient to the normal of the curve y = x^{3} - x^{2} at the point where x = 2....
The table shows the mark obtained by students in a test. Marks 1 2 3 4 5 Frequency ...