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Question
The graph of the polynomial f(x) = ax2 + bx + c is as shown in Fig. 2.20. Write the value of b2 − 4ac and the number of real zeros of f(x).
Solution
The graph of the polynomial f(x) = ax2 + bx + c or the curve touches x−axis at point `((-b)/2a,0)`. The x-coordinate of this point gives two equal zeros of the polynomial and `b^2 -4ac =0`.
Hence the number of real zeros of `f(x)`is 2 and `b^2 - 4ac = 0`
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