1.

logx 243 = 2.5, then value of x will be :(A) 9(B) 3(C) 1(D) 81

Answer»

Answer is (A) 9

∵ logan = x

⇒ ax = n

Similarly logx 243 = 2.5

⇒ 243 = x2.5

⇒ x5/2 = 243 = (3)5

Squaring on both sides,

(x5/2)2 = {(3)5}2

⇒ x5/2 = (32)2

On comparing, x = 32 = 9



Discussion

No Comment Found