Question

关于log既问题..

Answer 1

更新1:

咁如果 p = log 3
q=log5 [f] log6 [g] log12 应该点计!? 如果可以请尽量以：◇五dicky理◇兄既方法解答 又或者：◇五dicky理◇兄见到既话都可以答一答

(a) log75 = log(3*5*5)←因为75=3*5*5(方法系当佢叫你以p = log 3及q = log 5表示时试下将75除3或5直至除唔到) =log3 + log5 +log5←利用公式log (a*b)=log a + log b =p+2q←代番pq入log 3 log 5 (b) log开方75 =log 75^0.5←开方75=75ge0.5次方 =0.5log 75←利用公式log a^b=b log a =0.5(p+2q)←因为a已经计到log 75=p+2q
所以可以直接代入 =0.5p + q←化简 (c) log 0.15 =log(0.01*3*5)←同a一样方法 =log0.01+log3+log5 =p+q-2
参考: 我
a). log 75= log(3*25) = log ( 3*5*5) = log 3 + log 5 + log 5 =p + 2q b). log 开方75 = log (75)^1/2 = 1/2* log (75) = 1/2(p+2q) from part (a) c). log 0.15= log (0.3*0.5) = log (3*5/100) = log 3 +log 5 - log 100 = p+q -2
参考: me
(a) log 75= log (3X5X5) From log(M*N) = log M+log N Hence log 75= log 3+log5 +log5 = p+q+q = p+2q (b) log 开方75 = log (75) ^1/2 From log M^n = n log M Hence log 开方75 = 1/2 log 75 From (a) log 75 = p+2q Then log 开方75 = 1/2 log 75 = 1/2 (p+2q) = 1/2 (p) + q (c) log 0.15 = log 15 /100 From log M/N = log M - log N log 0.15 = log 15/100 = log 15 -log 100 = log (3X5) - log 100 = log 3 + log 5 - log 100 = p+ q -2
参考: 自己计的..
a. log75 = log(3*5*5) =log3 + log5 +log5 =p+2q b. log开方75 =log 75^0.5 =0.5log 75 =0.5(p+2q) (from a) c. log 0.15 =log(0.01*3*5) =log0.01+log3+log5 =p+q-2