Saturday, January 14, 2017

Precalculus, Chapter 3, 3.4, Section 3.4, Problem 62

Given
log(8x) - log(1 + sqrt(x)) = 2 ---------------------(1)
On simplification we get
=> As we know log(a) - log(b) = log(a/b)
so ,
=> log(8x) - log(1 + sqrt(x)) = 2
=> log((8x)/(1 + sqrt(x))) = 2
=> log((8x)/(1 + sqrt(x))) = log 10^2 [as 2= log_10 (10^2) ]
=> removing log on both sides we get
=>(8x)/(1 + sqrt(x)) = 10 ^2
=>8x = 100(1+sqrt(x))
=>(8x - 100 ) = 100 sqrt(x)
=> squaring on both sides we get
=> (8x-100)^2 = 10000x
=>64x^2 +10000 -1600x = 10000x
=>64x^2 +10000 - 11600x = 0
=>on simplification we get
x= +- (25/8)(29+5sqrt(33))

on verification by substituting the values of x in the equation (1)
we get x= + (25/8)(29+5sqrt(33))
as cannot be solved x= - (25/8)(29+5sqrt(33)) when "sqrt(x)"
so,
x= (25/8)(29+5sqrt(33))
=> x = 180.384

No comments:

Post a Comment

Summarize the major research findings of "Toward an experimental ecology of human development."

Based on findings of prior research, the author, Bronfenbrenner proposes that methods for natural observation research have been applied in ...