NIMCET 2011 — Mathematics PYQ
NIMCET | Mathematics | 2011The minimum value of px+qy, when xy=r2 is:
Choose the correct answer:
- A.
2rpq
(Correct Answer) - B.
2pqr
2rpq
Explanation
Step 1: Apply AM-GM to the terms px and qy
Let a=px and b=qy.
2px+qy≥(px)(qy)
Step 2: Simplify the expression
Multiply both sides by 2:
px+qy≥2pqxy
Step 3: Substitute the given constraint
We are given that xy=r2. Substitute this into the inequality:
px+qy≥2pq(r2)
px+qy≥2rpq
Conclusion:
The minimum value of the expression is 2rpq.
Correct Option:
(a) 2rpq
Explanation
Step 1: Apply AM-GM to the terms px and qy
Let a=px and b=qy.
2px+qy≥(px)(qy)
Step 2: Simplify the expression
Multiply both sides by 2:
px+qy≥2pqxy
Step 3: Substitute the given constraint
We are given that xy=r2. Substitute this into the inequality:
px+qy≥2pq(r2)
px+qy≥2rpq
Conclusion:
The minimum value of the expression is 2rpq.
Correct Option:
(a) 2rpq
