All categories

3 years ago

How would you evaluate f(-2) and f(a) for f(x) = 2x^2-x+5

1 answer:

7 0

$\bf f(x)=2x^2-x+5\\\\
-------------------------------\\\\
f(-2)=2(-2)^2-(-2)+5\implies f(-2)=2(-2)(-2)-(-2)+5
\\\\\\
f(-2)=2(4)+2+5\implies f(-2)=8+2+5\implies f(-2)=15
\\\\\\
f(a)=2(a)^2-(a)+5\implies f(a)=2a^2-a+5$

You might be interested in

The lengths of the sides of a triangle are consecutive integers, and the largest angle is twice the smallest angle. What is the

hjlf

Answer: $cosA = \frac{a+2}{2a}$

Step-by-step explanation:

Given that the lengths of the sides of a triangle are consecutive integers

Since side cannot be negative we can assume that the sides are

a, a+1 and a+2 where a>0

The largest angle is opposite side a+2 and smallest is angle opposite a

Using sine formula and the given information that the largest angle is twice the smallest angle

we get

$\frac{a}{sin A} =\frac{a+2}{sin 2A}$

Cross multiply to get

$\frac{sin 2A}{sin A } =\frac{a+2}{a}$

Since sin 2A = 2sin A cos A

we get

$2cosA = \frac{a+2}{a} \\cosA = \frac{a+2}{2a}$

8 0

3 years ago

If Roxanne earns $$$225.72 for working $$9 hours in a day, how much does she earn per hour?

Digiron [165]

Answer:

$25.08

Step-by-step explanation:

(the extra dollar signs aren't necessary)

All you have to do is 225.72 divided by 9 to find how much she makes per hour.

$\frac{225.72}{9} = 25.08$ is the amount she makes per hour.

5 0

3 years ago

The graph shows an image of a dilation about the origin with a scale factor of . What are the coordinates of the pre-image of ,

timama [110]

Answer:

A- (-8,-12)

Step-by-step explanation:

I got it right on the test

7 0

3 years ago

Drag each figure to show if it is similar to the figure shown or why it is not similar

pogonyaev

similar-6x3, 5x3, 12x15
not similar;different shapes-9x15, 3x5
not similar;different types of ratios-3x4

8 0

3 years ago

Read 2 more answers

At a swimming pool there are 2 managers 8 lifeguards 3 concession stand clerks and 2 maintenance people. If a person is selected

SashulF [63]

Step-by-step explanation:

The total number of people mentioned in this problem is 15. 15 will be the denominator for the probability in fraction form. The sum of the # of people that include lifeguards and managers will be the numerator.

Therefore, the probability that the person picked is either a manager or a lifeguard is 10/15 [because there are 2 managers and 8 lifeguards; 2 + 8 =10].

Fraction form of probability: 10/15

Decimal form: 0.6 repeated

Percent form: about 66.67%

4 0

3 years ago