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Pre-calc graph behavior

Write the equation of the graphed function. And describe the intervals where the function is increasing, decreasing or constant, intercepts, describe any asymptotes and end behavior.

Pre-calc graph behavior Write the equation of the graphed function. And describe the-example-1
User KNejad
by
7.9k points

1 Answer

3 votes

Answer:

Explanation:

This is a piecewise function, and it seems to consist of two linear segments.

For the first segment (from the leftmost point to the vertex):

The line starts at the point (-3, -3) and ends at the vertex (4, 5).

The slope, m, of this segment is given by:

=

change in

change in

=

5

(

3

)

4

(

3

)

=

8

7

m=

change in x

change in y

=

4−(−3)

5−(−3)

=

7

8

So the equation of the line in point-slope form is:

(

3

)

=

8

7

(

(

3

)

)

y−(−3)=

7

8

(x−(−3))

+

3

=

8

7

(

+

3

)

y+3=

7

8

(x+3)

For the second segment (from the vertex to the rightmost point):

The line starts at the vertex (4, 5) and continues downwards with a slope of -1 (since it's a 45° line declining).

So the equation in point-slope form is:

5

=

1

(

4

)

y−5=−1(x−4)

5

=

+

4

y−5=−x+4

Combining these, the piecewise function is:

(

)

=

{

8

7

(

+

3

)

3

for

4

+

9

for

>

4

f(x)={

7

8

(x+3)−3

−x+9

for x≤4

for x>4

Intervals of Increase, Decrease, or Constant:

Increasing:

4

x≤4

Decreasing:

>

4

x>4

Intercepts:

x-intercept: Where y = 0. For the first segment,

0

=

8

7

(

+

3

)

3

0=

7

8

(x+3)−3

Solving for x, you get x is approximately -0.375 or -3/8.

y-intercept: Where x = 0. For the first segment,

=

8

7

(

0

+

3

)

3

y=

7

8

(0+3)−3

y is approximately 1.14 or 8/7.

Asymptotes:

There are no asymptotes for linear functions.

End Behavior:

As

x→−∞,

(

)

f(x)→−∞

As

x→∞,

(

)

f(x)→−∞

User Dan Parker
by
7.7k points