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All the values of $$m$$ for which both roots of the equations $$x^2 - 2mx + m^2 - 1 = 0$$ are greater than $$-2$$ but less than $$4$$, lie in the interval
1. Factorize the Quadratic Equation
The given quadratic equation is:
$$x^2 - 2mx + m^2 - 1 = 0$$
Notice that the first three terms form a perfect square:
$$(x - m)^2 - 1 = 0$$
2. Find the Roots Directly
Isolate the perfect square term:
$$(x - m)^2 = 1$$
Take the square root of both sides:
$$x - m = \pm 1$$
This gives the two distinct roots directly:
$$\alpha = m - 1$$
$$\beta = m + 1$$
3. Apply the Given Boundary Conditions
The problem states that both roots must be strictly greater than $$-2$$ and strictly less than $$4$$.
For the smaller root $$\alpha = m - 1$$ to be greater than $$-2$$:
$$m - 1 > -2$$
$$m > -1$$
For the larger root $$\beta = m + 1$$ to be less than $$4$$:
$$m + 1 < 4$$
$$m < 3$$
4. Combine the Inequalities
Intersecting the two boundary requirements gives the final range for the parameter:
$$-1 < m < 3$$
Final Answer
All the values of $$m$$ lie in the interval $$(-1, 3)$$.
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