By definition of absolute value, you have

or more simply,

On their own, each piece is differentiable over their respective domains, except at the point where they split off.
For <em>x</em> > -1, we have
(<em>x</em> + 1)<em>'</em> = 1
while for <em>x</em> < -1,
(-<em>x</em> - 1)<em>'</em> = -1
More concisely,

Note the strict inequalities in the definition of <em>f '(x)</em>.
In order for <em>f(x)</em> to be differentiable at <em>x</em> = -1, the derivative <em>f '(x)</em> must be continuous at <em>x</em> = -1. But this is not the case, because the limits from either side of <em>x</em> = -1 for the derivative do not match:


All this to say that <em>f(x)</em> is differentiable everywhere on its domain, <em>except</em> at the point <em>x</em> = -1.
Put them into y=mx+b
y=1/3x -1
y=2/3x-4
Graph them. Where they touch is your answer. No touch? No solution. Same line? Infinite solutions.
Second set: Same thing.
Solution to first set is (9,2)
Answer:
They'll meet after 200 meters , if they simultaneously start running towards each other.
Step-by-step explanation:
Let x =distance travelled by dog and 200-x be the distance travelled by cat. Inorder to meet, the sum of their travelled distances shall be equal to 200 meters as they are far apart by 200 meters.
Dog: Distance =Speed x time: x=30t
Cat: Distance = 200-x
=24t
The sum of their distance travelled shall be 200 meters: 30t+ 24t= 200;54t=200;t=200/54=3.7secs
So they will meet after 3.7 seconds
To check:
Distance travelled by dog :x=30(3.7)
=111.11 meters
Distance travelled by cat: 24t=24(3.7)
=88.89 meters
Therefore since they are travelling towards each other and their distance apart is 200 meters, after 3.7 seconds they will meet because dog travelled 111.11 meters and cat travelled 88.89 meters and they covered already 200 meters as the sum of 111.11+ 88.89
=200 meters
Since it is a right angle you would subtract 57 from 90 because both angles added together are 90°. 90-57= 33°