40:28 are both divisible by 4. 40/4 is 10. 28/4 is 7. So the ratio would be 10:7 since neither is divisible by both the same number, this is the final ratio.

4 0

1 year ago

Determine the open intervals on which the graph of f(x) = x - 4cos x is concave upward or concave downward

bazaltina [42]

The graph of the function $f(x)$ is

concave upward, when $f''(x)>0;$
concave downward, when $f''(x)$

Find $f''(x):$

$f'(x)=(x-4\cos x)'=1+4\sin x;$

$f''(x)=4\cos x.$

Now:

1. when $4\cos x>0,$ the graph of the function is concave upward and this is for

$x\in \left(-\dfrac{\pi}{2}+2\pi k,\dfrac{\pi}{2}+2\pi k\right), \text{ where } k\in Z.$

2. when $4\cos x$ the graph of the function is concave downward and this is for

$x\in \left(\dfrac{\pi}{2}+2\pi k,\dfrac{3\pi}{2}+2\pi k\right), \text{ where } k\in Z.$

6 0

2 years ago

A city's population was 30,200 people in the year 2010 and is growing by 950 people a year. Give a formula for the city's popula

kolbaska11 [484]

the formula should look like this:

p=30200+950t

3 0

3 years ago

Read 2 more answers

Solve for x: 7x + 15 = 38

oksano4ka [1.4K]

All you do is move all the terms that don't contain " x " to the right side and solve.

x = $\frac{23}{7}$

Hope that helps, Good luck! (:

8 0

2 years ago

Read 2 more answers