Page 41 - CHAPTER 4 (Quadratic equations)

CHAPTER 4
QUADRATIC EQUATIONS

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11. If the roots of the quadratic equation ax +bx+c=0 are imaginary ,
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then for all values of a, b, c and x∈R, the expression a x +abx+ac is
(A) Positive (B) Non-negative

(C) Negative (D) NONE

12. Graph of y=a +bx+c is given below. What conclusions can be
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drawn from the graph

(i) a>0

(ii) b<0

(iii) c<0

(iv) b -4ac>0
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(A) (i) and (iv) only (B) (ii) and (iii) only

(C) (i) (ii) and (iv) (D) (i),(ii),(iii),(iv)

13. Figure given below shows the graph of y=a +bx+c. Then which of
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the following is correct?

(i) a>0

(ii) b<0

(iii) c>0

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(iv) b -4ac<0
(A) (i) and (iv) (B) (ii) and (iii)

(C) (iii) and (iv) (D) NONE

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2
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14. If the roots of the equation (c -ab)x -2(a -bc)x+(b -ac)=0 for a≠ 0 are
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real and equal, then the value of a +b +c is
3
3
3
(A) abc (B) 3abc (C) 0 (D) 2
15. The number of integral values of k for which the equation (k-
2)x +8x+k+4=0 has both the roots real, distinct and negative is
2

(A) 1 (B) 2 (C) 3 (D) 4

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