99 Percentile Qs Bank for JEE MainMathematicsLimits
If p, q, r, s > 0 , then lim x → ∞ p 1 x + q 1 x + r 1 x + s 1 x 4 3 x is equal to
Options
- Apqrs
- Bpqrs 3
- Cpqrs 3 2
- Dpqrs 3 4
Correct answer
D. pqrs 3 4
Step-by-step solution
Consider the given expression, lim x → ∞ p 1 x + q 1 x + r 1 x + s 1 x 4 3 x [where, p, q, r, s > 0] Put, 1 x = z , so that x → ∞ ⇒ z → 0 = lim z → 0 p z + q z + r z + s z 4 3 z which is in the form 1 ∞ . =e lim z → 0 p z + q z + r z + s z 4 − 1 3 z = e lim z → 0 p z - 1 z + q z - 1 z + r z - 1 z + s z - 1 z 3 4 = e 3 4 log e p + log e q + log e r + log e s = e 3 4 log e pqrs = pqrs 3 4