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tresset_1 [31]
3 years ago
12

Find all solutions to the equation. cos^2x + 2 cos x + 1 = 0

Mathematics
1 answer:
Black_prince [1.1K]3 years ago
3 0

Answer:

x = pi, 3pi, 5pi  etc

x = -pi, -3pi, -5pi etc

Step-by-step explanation:

cos^2 x + 2 cos x + 1 = 0

replace cos x with m

m^2 + 2m +1 = 0

solve by factoring  (this is a^2 +2ab+b^2 = (a+b)^2  where a =m and b=1)

(m+1)^2=0

take the square root of each side

m+1 =0

m=-1

now replace m with cos x

cos x = -1

take arccos  of each side

arccos cos x = arccos (-1)

x = pi, 3pi, 5pi  etc


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Work
liubo4ka [24]

Answer:

Step-by-step explanation:

the quotient of is the result of dividing two terms

The first term is - Twice a number t: 2t

The second term is - and 12: 12 2t÷12or 2t12

7 0
3 years ago
one leg of a right triangle is 5 millimeters shorter than the longer leg and the hypotneuse is 5 millimeters longer than the lon
Makovka662 [10]
The answer, in short, is that the short leg equals 15 mm, the long leg equals 20 mm, and the hypotenuse equals 25mm. but if you'd like to see how I solved it, here are the steps.
-----------------------------
The Pythagorean theorem (also known as Pythagoras's Theorem) can be used to solve this. This theorem states that one leg or a right triangle squared plus the other side of that same triangle squared equals the hypotenuse of that triangle squared. To put it in equation form, L² + L² = H².

Let's call the longer leg B, the shorter leg A, and the hypotenuse H.
From the question, we know that A = B - 5, and H = B + 5. 

So if we put those values into an equation, we have (B - 5)² + B² = (B + 5)²

Now, to solve. Let's square the two terms in parentheses first:
(B² - 5B - 5B + 25) + B² = B² + 5B + 5B + 25

Now combine like terms:
2B² -10B + 25 = B² + 10B + 25

And now we simplify. Subtract 25 from each side:
2B² - 10B = B² + 10B

Subtract B² from each side:
B² - 10B = 10B

Add 10B to each side:
B² = 20B

And finally, divide each side by B:
B = 20

So that's the length of B. Now to find out A and H.
A = B - 5, so A = 15.
H = B + 5, so H = 25.

And your final answer is A = 15mm, B = 20mm, and H = 25mm
7 0
3 years ago
1. What is the binomial expansion of (x + 3)5? ​
lara [203]

Answer:

5x + 15

Step-by-step explanation:

To expand the binomial, you need to multiply each term inside the parentheses by 5.

(x + 3)5

= (x * 5) + (3 * 5)

= 5x + 15

4 0
2 years ago
What is the equation of the line that passes through the point (4,3) and has a slope<br> of 1?
Mamont248 [21]

Answer (<u>assuming it can be in point-slope form)</u>:

y-3 = 1(x-4)  

Step-by-step explanation:

Use the point-slope formula y-y_1 = m (x-x_1) to write the equation of the line. Substitute real values for m, x_1, and y_1 in the formula.

Since m represents the slope, substitute 1 in its place. Since x_1 and y_1 represent the x and y values of a point the line intersects, substitute the x and y values of (4,3) in its place. Substitute 4 for x_1 and 3 for y_1. This gives the following equation and answer in point-slope form:

y-3 = 1(x-4)

5 0
3 years ago
Subtract -5x2<br> 5x2 – 9x + 8 from -6x2 + 5.<br> Answer:<br> Submit Answer<br> what’s the answer
Burka [1]

Answer:

-11x^{2} +9x-3

Step-by-step explanation:

(-6x^{2}+5)- (5x^{2}-9x+8) =-11x^{2} +9x-3

8 0
3 years ago
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