AP EAMCET · Maths · Quadratic Equation

Let $p$ and $q$ be roots of the equation $x^{2} - 2 x + A = 0$ and let $r$ and $s$ be the roots of the equation $x^{2} - 18 x + B = 0 .$ If $p < q < r < s$ are in $A P,$ then $A$ and $B$ are

A $- 3, - 77$
B $3, - 77$
C $- 3, 77$
D $3, 77$

Verified Solution

Answer & Solution

Correct Answer

(C) $- 3, 77$

Step-by-step Solution

Detailed explanation

Let the four numbers in A.P. be p=a-3d, q=a-d, r=a+d, s=a+3d. Now, p and q are the roots of the quadratic equation x2-2x+A=0. Therefore, using the sum and product of roots of a quadratic equation, we get p+q=2 …i…

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

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Let p and q be roots of the equation x2-2x+A=0 and let r and s be the roots of the equation x2-18x+B=0. If p<q<r<s are in AP, then A and B are

Step-by-step Solution

Let $p$ and $q$ be roots of the equation $x^{2} - 2 x + A = 0$ and let $r$ and $s$ be the roots of the equation $x^{2} - 18 x + B = 0 .$ If $p < q < r < s$ are in $A P,$ then $A$ and $B$ are