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3 years ago

Find the exact values of sin 2θ and cos 2θ for cos θ = 6/13

Mathematics

1 answer:

Oksanka [162]3 years ago

4 0

Answer:

Step-by-step explanation:

cos^-1(6/13)=62.5136°

sin(2*62.5136°)=0.8189

cos(2*62.5136°)=-0.5740

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PLEASE HELP/ANSWER! From 1980 to 1990, Lior’s weight increased by 25%. If his weight was k kilograms in 1990, what was it in 198

Elena-2011 [213]

The weight in 1980 is $\frac{4k}{5}$ kilograms

Solution:

From 1980 to 1990, Lior’s weight increased by 25%

His weight is "k" kilograms in 1990

To find: weight in 1980

This is a percentage increase problem

Let "x" be the weight in kilograms in 1980

The percentage increase is given by formula:

$\text{Percentage increase } = \frac{\text{Final value - initial value}}{\text{initial value}} \times 100$

Here,

Initial value in 1980 = x

Final value in 1990 = k

Percentage increase = 25 %

Substituting the values in formula,

$25 = \frac{k-x}{x} \times 100\\\\25x = 100(k-x)\\\\x = 4(k-x)\\\\x = 4k - 4x\\\\5x = 4k\\\\x = \frac{4k}{5}$

Thus the weight in kilograms in 1980 is $\frac{4k}{5}$

7 0

3 years ago

Write the quadratic equation whose roots are 2 and -4 and whose leading coefficient is 2

Goryan [66]

Answer:

2x^2+4x-16

Step-by-step explanation:

The quadratic can be written as

f(x) = a(x-z1)(x-z2) where z1 and z2 are the roots

f(x) = a (x-2)(x- -4)

a is the leading coefficient

f(x) = 2(x-2)(x+4)

= 2(x^2 -2x+4x-8)

= 2(x^2 +2x-8)

= 2x^2 +4x-16

5 0

3 years ago

When y = 35,x = 2.5. If the value of y varies directly with x what is the value of y when the value of xis 3.25

leonid [27]

Answer:

The value of y would be 45.5

Step-by-step explanation:

To solve this problem, start with the base form of direct variation.

y = kx

Now we can use our original values to model the equation and find k.

35 = k(2.5)

14 = k

Now we can model the equation as:

y = 14x

Now to find y, when x = 3.25, simply put 3.25 into the equation.

y = 14(3.25)

y = 45.5

8 0

4 years ago

Expand: f(x) = x^4 - 3x + x^2 +

Delicious77 [7]

Step-by-step explanation:

f (x) =y

y=x^4 -3x + x^2

incomplete

6 0

3 years ago

Read 2 more answers

Simplify 14-2 times 3

kumpel [21]

14 - 6 = 8 this is the answer

5 0

3 years ago