Answer:
Hey There!
Let's solve....
[tex]f(x) = \frac{(x + b)(x + c)}{(b - a)(c - a)} + \frac{(x + c)(x + a)}{(c - b)(a - b)} + \frac{(x + a)(x + b)}{(a - c)(b - c)} - 1[/tex]
[tex]f( - a) = \frac{( - a + \cancel{b})( \cancel{ - a} + c)}{ (\cancel{b} - a)(c - \cancel{a})} + 0 + 0 - 1 = 1 - = 0 [/tex]
[tex]f( - b) = 0 + \frac{( \cancel{ - b} + c)( \cancel{ - b} + a)}{ (c - \cancel{b})(a - \cancel{b})} + 0 - 1 = 1 - 1 = 0 [/tex]
[tex]f( - c) = 0 + 0 + \\ \frac{ (\cancel{ - c} + a)( \cancel{ - c} + b)}{(a - \cancel{c})(b - \cancel{c})} - 1 \\ \\ = 1 - 1 = 0 [/tex]
[tex]f(x) \to {max}^{m} \: power = 2 \\ [/tex]
Maximum power where quadratic equation is 2
[tex] \therefore \: f(x) = 0 \\ [/tex]
x belongs r
Now let's identify
[tex] \to \: \frac{(x + b)(x + c)}{(b - a)(c - a)} + \frac{(x + c)(x + a)}{(c - b)(a - b)} + \frac{(x + a)(x + b)}{(a - c)(b - c)} - 1 = 0 [/tex]
So x belongs r is identified
Hence finally solved...
I hope it is helpful to you..
cheers!__________