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2 years ago

I'm new to this and I dont really understand this

Mathematics

1 answer:

agasfer [191]2 years ago

5 0

Answer:

So starting off with 1a f(4)

We simply substitute x with 4 for the function

f(4)=2(4)-5

f(4)=8-5

f(4)=3

Next 1b, here it's a little different since you have to multiply the functions I think ( please correct me if I'm wrong).

gf(4), basically means functions g and f are being multiplied and their variables are being substituted with 4.

g(4)=4^2+3

g(4)=16+3

g(4)=19

and we also know from before that f(4)=3, so we'll do 19 times 3 which is 57

For the next two, I may be wrong, but I'm still going to try:

anything to the power of a negative is a fraction so for f^-1(x)=2x-5 we'll have 1/f(x)=x/2+5/2

And then for g^-1, we'll have 1/g(x)= $\sqrt{x-3} \sqrt{x-3}$

Hope I helped :)

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Find the value of x

Karo-lina-s [1.5K]

Answer:

x = 68°

Step-by-step explanation:

∠ DCB = ∠ EDC = 27° ( alternate angles )

Thus ∠ ECB = 23° + 27° = 50°

The sum of the 3 angles in a triangle = 180°, thus

x = 180° - (62 + 50)° = 180° - 112° = 68°

7 0

3 years ago

Read 2 more answers

If f (x) = 8(5x-2) find f -1 (x).

saw5 [17]

Step-by-step explanation:

f(x)=8(5x-2)

interchanging the role of x&y

x=8(5y-2)

x=40y-16
x+16=401y
y=(x+16)/40

f-1(x)=(x+16)/10

<h3>stay safe healthy and happy.</h3>

6 0

3 years ago

Find the population mean or sample mean as indicated. Sample: 19, 15, 6, 11, 24 Compute the sample mean for this data set. Selec

yKpoI14uk [10]

Answer:

$\overline{x}=15$

Step-by-step explanation:

the mean is given by:

$\overline{x} = \dfrac{\sum\limits_{i=1}^n x_i}{n} \quad\text{or}\quad \dfrac{\text{sum of all items}}{\text{number of items}}$

In our case this is:

$\overline{x} = \dfrac{19+15+6+11+24}{5} \Rightarrow \dfrac{75}{5}\\\\\overline{x} = 15\\\\$

side note: the main difference between sample mean and population mean is in the 'context'. However, the method to calculate them is the same.

By context I mean: if this the items are taken from some larger category for example: the ages of a few 'students' from a 'class'. Here 'students' are the sample from a larger set that is 'class'. The mean of the 'few students' will be called sample mean. In contrast, if we take the mean of the ages of the whole class then this is called population mean. (population mean == mean of the whole set)

In our case we aren't told exactly where these numbers come from, is this the whole set or a sample from it, the lack of context allows us to assume that the mean can either be population mean or sample mean. So we can safely use any symbol $\mu$ or $\overline{x}$ .