S Chand ICSE Mathematics Class 9 Solution Seventh Chapter Logarithms Exercise 7A (O.P. Malhotra, S.K. Gupta, Anubhuti Gangal)

S Chand ICSE Mathematics Class 9 Solution Seventh Chapter Logarithms Exercise 7A

(1) Give an equivalent exponential form for each statement:

(i) log₂ 8 = 3

(ii) log₃ 81 = 4

(iii) log₂ ½ = -1

(iv) log₅ 1/25 = -2

(v) ½ = log₄ 2

(vi) 1/3 = log₂₇ 3

Solution:

(2) Give an equivalent logarithmic form for each statement

(i) 16 = 2⁴

Or, log₂ 16 = 4

(ii) 25 = 5²

Or, log₅ 25 = 2

(iii) 81 = 3⁴

Or, log₃ 81 = 4

(iv) 6⁰ = 1

(v) 8^1/3

(vi) 1/9 = 3^-2

(vii) 1/32 = 2^-5

(viii) 10^1.4969 = 31.4

Solution:

(3) Find the value of each logarithms given below:

(v) log₁₀ 100 = x

Or, 10^x = 10²

X = 2

(vi) log₂ 0.5 = x

2^x = 0.5 = 5/10 = ½ = 2^-1

(5) log₁₀x = a

10^a = x (True)