You should find that the derivative is entirely negative whenever x < 0. This suggests that the function f(x) is decreasing on this interval. So that takes care of part (b).

The interval x < 0 is the same as -infinity < x < 0 which then translates to the interval notation (-infinity, 0)

Similarly, you should find that the derivative is positive when x > 0. So the function is increasing on the interval (0, infinity)

6 0

2 years ago

The diagram shows the graph of y = 2x + c, where c is a constant find the value of K.

mote1985 [20]

Answer:

$k=\frac{13}{2}$

Step-by-step explanation:

The equation $y=2x+c$ is a linear equation. By definition, the independent term on this equation (that is, the number that is not being multiplied by $x$ ) is the y-intercept, which is a fancy way of saying "the point where the line crosses the y-axis".

By looking at the equation, we know that our y-intercept is c. By looking at the graph, we can see that the y-intercept is -3. Therefore, $c=-3$ and we get the complete version of our linear equation:

$y=2x-3$

Now, looking at the graph we can see that the point $(k,10)$ lies on the line of the equation, which means that the point is a solution to our equation. All we have to do is replace $x$ and $y$ by the values of the given point (which are $k$ and $10$ , respectively), and then solve for $k$ :

$10=2k-3\\10+3=2k\\13=2k\\2k=13\\k=\frac{13}{2}$

And we are done!

4 0

2 years ago

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