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If the points (a,a^(2)) and (1,2) lie in...

If the points `(a,a^(2)) and (1,2)` lie in the same angular region between the lines `3x+4y-1=0` and `2x+y-3=0` , then

A

`a lt -3` or , `a gt 1`

B

`a in [-3,1]`

C

`a lt (1)/(4)` or , ` a gt -1`

D

none of these

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To solve the problem, we need to determine the range of \( a \) such that the points \( (a, a^2) \) and \( (1, 2) \) lie in the same angular region between the lines \( 3x + 4y - 1 = 0 \) and \( 2x + y - 3 = 0 \). ### Step 1: Determine the position of the point \( (1, 2) \) with respect to the lines. 1. **Substituting \( (1, 2) \) into the first line \( 3x + 4y - 1 = 0 \)**: \[ 3(1) + 4(2) - 1 = 3 + 8 - 1 = 10 > 0 \] This means the point \( (1, 2) \) is on the positive side of the line. 2. **Substituting \( (1, 2) \) into the second line \( 2x + y - 3 = 0 \)**: \[ 2(1) + 2 - 3 = 2 + 2 - 3 = 1 > 0 \] This means the point \( (1, 2) \) is also on the positive side of the second line. ### Step 2: Determine the conditions for the point \( (a, a^2) \). 1. **Substituting \( (a, a^2) \) into the first line \( 3x + 4y - 1 = 0 \)**: \[ 3a + 4a^2 - 1 > 0 \implies 4a^2 + 3a - 1 > 0 \] 2. **Substituting \( (a, a^2) \) into the second line \( 2x + y - 3 = 0 \)**: \[ 2a + a^2 - 3 > 0 \implies a^2 + 2a - 3 > 0 \] ### Step 3: Solve the inequalities. 1. **For the inequality \( 4a^2 + 3a - 1 > 0 \)**: - Find the roots using the quadratic formula: \[ a = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} = \frac{-3 \pm \sqrt{3^2 - 4 \cdot 4 \cdot (-1)}}{2 \cdot 4} = \frac{-3 \pm \sqrt{9 + 16}}{8} = \frac{-3 \pm 5}{8} \] - Roots are: \[ a_1 = \frac{2}{8} = \frac{1}{4}, \quad a_2 = \frac{-8}{8} = -1 \] - The quadratic opens upwards, so the solution is: \[ a < -1 \quad \text{or} \quad a > \frac{1}{4} \] 2. **For the inequality \( a^2 + 2a - 3 > 0 \)**: - Find the roots: \[ a = \frac{-2 \pm \sqrt{2^2 - 4 \cdot 1 \cdot (-3)}}{2 \cdot 1} = \frac{-2 \pm \sqrt{4 + 12}}{2} = \frac{-2 \pm 4}{2} \] - Roots are: \[ a_1 = 1, \quad a_2 = -3 \] - The quadratic opens upwards, so the solution is: \[ a < -3 \quad \text{or} \quad a > 1 \] ### Step 4: Combine the conditions. - From the first inequality, we have \( a < -1 \) or \( a > \frac{1}{4} \). - From the second inequality, we have \( a < -3 \) or \( a > 1 \). Combining these results: - For \( a < -1 \): The stricter condition is \( a < -3 \). - For \( a > \frac{1}{4} \): The stricter condition is \( a > 1 \). ### Final Answer: Thus, the ranges of \( a \) such that both points lie in the same angular region are: \[ a < -3 \quad \text{or} \quad a > 1 \]

To solve the problem, we need to determine the range of \( a \) such that the points \( (a, a^2) \) and \( (1, 2) \) lie in the same angular region between the lines \( 3x + 4y - 1 = 0 \) and \( 2x + y - 3 = 0 \). ### Step 1: Determine the position of the point \( (1, 2) \) with respect to the lines. 1. **Substituting \( (1, 2) \) into the first line \( 3x + 4y - 1 = 0 \)**: \[ 3(1) + 4(2) - 1 = 3 + 8 - 1 = 10 > 0 \] ...
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OBJECTIVE RD SHARMA ENGLISH-STRAIGHT LINES-Chapter Test
  1. If the points (a,a^(2)) and (1,2) lie in the same angular region betwe...

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  2. The equation to a pair of opposite sides of a parallelogram are x^2-5x...

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  3. The distance between the parallel lnes y=2x+4 and 6x-3y-5 is (A) 1 (B)...

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  4. P is a point on either of the two lines y - sqrt(3)|x| = 2 at a dista...

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  5. If one diagonal of a square is along the line x=2y and one of its vert...

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  6. The line which is parallel to x-axis and crosses the curve y=sqrt(x) a...

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  7. P(3,1),Q(6,5) and R(x,y) are three points such that PRQ is a right ang...

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  8. Find the equation of the straight line which passes through the point ...

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  9. What is the equation of the straight line which is perpendicular to y=...

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  10. Find the perpendicular distance between the lines 3x+4y+9=0 and to 6x...

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  11. The equation of the line passing through the point (1,2) and perpendic...

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  12. The straight lines x+y=0, 3x+y-4=0 and x+3y-4=0 form a triangle which ...

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  13. Triangle formed by x^(2)-3y^(2)=0 and x=4 is

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  14. The co-ordinates of the orthocentre of the triangle bounded by the lin...

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  15. the lines (p+2q)x+(p-3q)y=p-q for different values of p&q passes troug...

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  16. Write the distance between the lines 4x+3y-11=0\ a n d\ 8x+6y-15=0.

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  17. If the diagonals of a parallelogram ABCD are along the lines x+5y=7 a...

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  18. The straight lines x+y-4=0, 3x+y-4=0 and x+3y-4=0 form a triangle, whi...

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  19. Write the coordinates of the orthocentre of the triangle formed by ...

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  20. A point equidistant from the line 4x + 3y + 10 = 0, 5x-12y + 26 = 0 an...

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  21. The number of values of a for which the lines 2x+y-1=0 , a x+3y-3=0, a...

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