How do you graph y=log_2 (x-2)y=log2(x2)?

2 Answers
Dec 10, 2017

Answer Below:

Explanation:

We know how to sketch log_2 x log2x rather simply:

graph{lnx [-4.04, 15.96, -4.88, 5.12]}

But log_2 (x-2) log2(x2) is just log_2 x log2x shifted 22 to the right:

log_2 (x-2 )log2(x2): graph{ln(x-2) [-4.04, 15.96, -4.88, 5.12]}

The asymptote for log_2 x log2x is x=0x=0
The xx intercept is 11

So the asymptote for log_2 (x-2)log2(x2) is x=2 x=2
The new xx intercept is hence 33

As indicated on the second graph

Dec 10, 2017

See below

Explanation:

y=log_2(x-2)y=log2(x2)

First, Let's find the domain:
x-2>0quad=>quadx>2

Now we know that this logaritmic function will be approching x=2 but will never get there.The base equals 2 which is greater than 1 so that means It's increasing its value on the whole domain.

Intercept x axis: [3,0]
We can find it by equation but it's much easier to simply think like this: ifquadlogxquad"must equal 0 then x must equal 1"quadwhich means x-2=1quad=>quad x=3

Doesn't intercept y axis

Next point could be when y=1. (Let's do an equation this time)
y=log_axquad=>quad1=log_2(x-2)quad
a^y=xquad=>quad2^1=x-2

y=1quad=>quadx=4