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प्रश्न
Without sketching the graph, find whether the graph of the following function will intersect the x-axis and if so in how many points
y = x2 − 3x − 7
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उत्तर
y = x2 – 3x – 7
y = x2 – 3x – 7 ......(2)
Compare this equation with the equation ax2 + bx + c = 0
We have a = 1, b = – 3, c = – 1
b2 – 4ac = (– 3)2 – 4(1)(– 1)
= 9 + 4
b2 – 4ac = 13 > 0
Since the discriminant is positive the quadratic equation has real and distinct roots and therefore the graph intersect the x-axis at two different points.
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