find the range of parameter a fr which the variable line y=2x+a lies btw the circle x(sqr)+y(sqr

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Discussion Response Post to: find the range of parameter a fr which the variable line y=2x+a lies btw the circle x(sqr)+y(sqr

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kabi (1665)

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hello

i m not going to solve this prob just giving the approach

first of all draw the circles so that u can actually visualise where a should lie .

we want y = 2x+a neither to touch the circles nor intersect any of them

put y = 2x +a in the eq. x²+y²-2x-2y+1 =0

u will get

5x² +4xa -6x+a² -2a +1 =0

for fulfilling the condition we want the d < 0 of this quadractic

so a²+2a -4 >0

solve this a >sqrt(5)-1 or a < - (sqrt(5)+1)

if we want such value of a so that lie b/w the circles u can easily come to conclusion

we want a < - (sqrt(5)+1) only .

then do the same thing for second circle . and find the value of a . ask me again if u have prob.

The time u guys take to find the derivative of a function or for finding the equilibrium constant of a reaction or for finding the angle of dispersion of prism or for standing from ur seat to congratulate our team after their win almost in that time one kid die because of poverty.

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