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3 years ago

Can someone help me?

Mathematics

1 answer:

hoa [83]3 years ago

5 0

Answer:

Step-by-step explanation:

If arccos (√3 / 2) = β, then cos β = adjacent side / hypotenuse = √3 / 2. This tells us immediately that the adjacent side length is √3 and the hypotenuse is 2. Via the Pythagorean Theorem, we know that the third side is 1.

This information rules out the 1st and 3rd answer choices.

Because cos 30° = adj / hyp = √3 / 2, we can conclude that the correct answer is the 4th one: 30°, 60°, 90°

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Given a table of values of a quadratic function, which of the following do you absolutely need in order to find its equation? *

nadya68 [22]

Answer:

The general form of a quadratic function is --> y = ax2 + bx + c

Since (0, -2) exists for the function, we can plug in those values:

-2 = a(0)2 + b(0) + c

-2 = 0 + 0 + c

-2 = c

So now our function so far is --> y = ax2 + bx - 2

We have two pairs of coordinates left: (-1, -8) and (3, -8).

First, plug in the first pair and simplify as much as you can:

-8 = a(-1)2 + b(-1) - 2

-8 = a - b - 2 ( add 2 to both sides )

-6 = a - b (stop here because we can't go further)

Second, plug in the second pair and simplify as much as you can:

-8 = a(3)2 + b(3) - 2

-8 = 9a + 3b - 2 ( add 2 to both sides )

-6 = 9a + 3b (stop here because we can't go further)

Now we have these two equations left:

a - b = -6

9a + 3b = -6

Now we solve for a and b using systems of equations, using one of three ways:

substitution

elimination

graphing (not my favorite, but it is doable)

Using substitution:

a - b = -6 can be rewritten as a = b - 6

plug into the second equation and solve for b

9(b - 6) + 3b = -6 (distribute the 9)

9b - 54 + 3b = -6 (combine all of the b's)

12b - 54 = -6 (add 54 to both sides)

12b = 48 (divide by 12 on both sides to isolate b)

b = 4

plug b into one of the original two equations

a - 4 = -6 (add 4 to both sides)

a = -2

The quadratic equation for this table is y = -2x2 + 4b - 2

6 0

2 years ago

Calvin had 30 minutes in time-out. For the first 23 1/3 minutes, Calvin counted spots on the ceiling. For the rest of the time,

scoundrel [369]

Answer: $\frac{20}{3}\ minutes$ or $6 \frac{2}{3}\ minutes$

Step-by-step explanation:

For this exercise you can convert the mixed number to an improper fraction:

1. Multiply the whole number part by the denominator of the fraction.

2. Add the product obtained and the numerator of the fraction (This will be the new numerator).

3. The denominator does not change.

Then:

$23\frac{1}{3}= \frac{(23*3)+1}{3}= \frac{70}{3}\ minutes$

You know that he had 30 minutes in time-out, he counted spots on the ceiling for $\frac{70}{3}$ minutes and the rest of the time he made faces at his stuffed tiger.

Then, in order to calculate the time Calvin spent making faces at his stuffed tiger, you need to subract 30 minutes and $\frac{70}{3}$ minutes:

$30\ min-\frac{70}{3}=(\frac{3(30)-70}{3})=\frac{20}{3}\ minutes$ or $6 \frac{2}{3}\ minutes$

7 0

3 years ago

Read 2 more answers

How would I figure out a linear equation with two plot points with fractions? (1/3(6),3) and (1/2(19),-2) are my two plot points

murzikaleks [220]

Answer: $m=\frac{-30}{79},\ y=5.40$

Step-by-step explanation:

Given

Points are $\left(6\frac{1}{3},3\right),\ \left(19\frac{1}{2},-2\right)$

Convert mixed numeral to fraction

$\left(6\frac{1}{3},3\right)\Rightarrow \left(\dfrac{19}{3},3\right)\\\\\left(19\frac{1}{2},-2\right)\Rightarrow \left(\dfrac{39}{2},-2\right)$

Slope of the line is

$\Rightarrow m=\dfrac{3-(-2)}{\dfrac{19}{3}-\dfrac{39}{2}}\\\\\Rightarrow m=\dfrac{5}{\dfrac{38-117}{6}}\\\\\Rightarrow m=\dfrac{-30}{79}$

Equation of line

$\Rightarrow \dfrac{y-3}{x-\dfrac{19}{3}}=\dfrac{-30}{79}\\\\\text{for y-intercept, put x=0}\\\\\Rightarrow \dfrac{y-3}{0-\dfrac{19}{3}}=\dfrac{-30}{79}\\\\\Rightarrow y-3=\dfrac{190}{79}\\\\\Rightarrow y=3+2.40\\\Rightarrow y=5.40$

3 0

2 years ago

Is 3 squared times 4 squared equal 12 squared ? Evaluate each side of the equation to explain your answer.

Nikolay [14]

Answer:

Nopes 3²+4²≠12²

Step-by-step explanation:

12²=144

3²+4²=

9+16=25

25≠144

To make it easier to see exactly WHY 3²+4²≠12² you can spread out the numbers in the equation.

(3·3)+(4·4)≠(12·12)

When solving equations you use PEMDAS (Parenthesis Exponents Multiplication Division Addition Subtraction). You have to solve in THAT ORDER.

7 0

2 years ago

Read 2 more answers

8x+10y=<br> 8x+10y=<br> \,\,70<br> 70

notsponge [240]

Answer:

Step-by-step explanation:

4 0

3 years ago