Mathematics
If x2 - 2x - 3 = 0; values of x correct to two significant figures are :
3.0 and 1.0
-1.0 and 3.0
3.0 or -1.0
3.00 or -1.00
Quadratic Equations
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Answer
Given,
⇒ x2 - 2x - 3 = 0
⇒ x2 - 3x + x - 3 = 0
⇒ x(x - 3) + 1(x - 3) = 0
⇒ (x + 1)(x - 3) = 0
⇒ x + 1 = 0 or x - 3 = 0
⇒ x = -1 or x = 3.
Rounding off to two significant figures, we get :
⇒ x = -1.0 or x = 3.0
Hence, Option 3 is the correct option.
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