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ziro4ka [17]
3 years ago
13

Evaluate 2x2 - 1 when x = 3.

Mathematics
2 answers:
Alla [95]3 years ago
6 0

Answer:11

Step-by-step explanation:2(3)x2-1=11

Charra [1.4K]3 years ago
4 0

Hello!

2.x^2 - 1 = 2.3^2 - 1 = 2.9 - 1 = 18-1 = 17

Good luck!

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My question is 7/8*8/9
Tom [10]
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3 years ago
Find all solutions of each equation on the interval 0 ≤ x < 2π.
Korvikt [17]

Answer:

x = 0 or x = \pi.

Step-by-step explanation:

How are tangents and secants related to sines and cosines?

\displaystyle \tan{x} = \frac{\sin{x}}{\cos{x}}.

\displaystyle \sec{x} = \frac{1}{\cos{x}}.

Sticking to either cosine or sine might help simplify the calculation. By the Pythagorean Theorem, \sin^{2}{x} = 1 - \cos^{2}{x}. Therefore, for the square of tangents,

\displaystyle \tan^{2}{x} = \frac{\sin^{2}{x}}{\cos^{2}{x}} = \frac{1 - \cos^{2}{x}}{\cos^{2}{x}}.

This equation will thus become:

\displaystyle \frac{1 - \cos^{2}{x}}{\cos^{2}{x}} \cdot \frac{1}{\cos^{2}{x}} + \frac{2}{\cos^{2}{x}} - \frac{1 - \cos^{2}{x}}{\cos^{2}{x}} = 2.

To simplify the calculations, replace all \cos^{2}{x} with another variable. For example, let u = \cos^{2}{x}. Keep in mind that 0 \le \cos^{2}{x} \le 1 \implies 0 \le u \le 1.

\displaystyle \frac{1 - u}{u^{2}} + \frac{2}{u} - \frac{1 - u}{u} = 2.

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Solve this equation for u:

\displaystyle \frac{u^{2} + 1}{u^{2}} = 2.

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u^{2} = 1.

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\cos^{2}{x} = 1,

x = k \pi, where k\in \mathbb{Z} (i.e., k is an integer.)

Given that 0 \le x < 2\pi,

0 \le k.

k = 0 or k = 1. Accordingly,

x = 0 or x = \pi.

8 0
2 years ago
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Answer:

1

Step-by-step explanation:

Mode is 1 as 1 has repeated the most number of times

7 0
3 years ago
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Let f(x)=cosx. Determine the x-value(s) where the function has a maximum or minimum value on [0,2π).
Ludmilka [50]

Answer:

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3 0
2 years ago
The triple beam balance shown above measures in grams what is the mass of the chick ?
ipn [44]
We have that

the first balance indicates--------> 10 g

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the answer is
17.5 g</span>
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2 years ago
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