All categories

2 years ago

Given tan θ = 2 and sin θ < 0. Find cos(θ +pi/4)

Mathematics

1 answer:

Lera25 [3.4K]2 years ago

5 0

Answer:

√10 / 10

Step-by-step explanation:

tan θ > 0 and sin θ < 0, so θ is in quadrant III. That means cos θ < 0.

cos(θ + π/4)

Use angle sum formula.

cos θ cos(π/4) − sin θ sin(π/4)

½√2 cos θ − ½√2 sin θ

Factor.

½√2 cos θ (1 − tan θ)

½√2 cos θ (1 − 2)

-½√2 cos θ

Write in terms of secant.

-½√2 / sec θ

Use Pythagorean identity (remember that cos θ < 0).

-½√2 / -√(1 + tan²θ)

-½√2 / -√(1 + 2²)

½√2 / √5

√10 / 10

You might be interested in

19 A triangle has coordinate points at A 1, 3) B(3, 6) and C(3, 3). What is distance between of AC? (8 Points)

lawyer [7]

Answer:

4 I think

Step-by-step explanation:

hope this help's

3 0

2 years ago

17 Q Graph the inequality n a coordinate plane

aliina [53]

The resultant graph is shown in the attached image.

Explanation:
Before we begin, remember that when we multiply by a negative sign, we flip the sign of the inequality
The given inequality is:
-y ≤ 3x - 5
We will multiply both sides by -1 to get a positive y vale. This will give us:
y ≥ -3x + 5

Now, to graph the inequality, we will first draw the line y = -3x + 5 and then shade the region having y values greater than the line.
To know the region, you will simply use trial and error method for random points on the two sides of the line.

The final solution would be as shown in that attachment.

Hope this helps :)

7 0

2 years ago

Construct a 95% confidence interval to estimate the population mean using the data below. x overbarequals37 sigmaequals10 nequa

kap26 [50]

Answer:

With 95% confidence when n equals 44, the population mean is between a lower limit of 33.96 and an upper limit of 40.04

Step-by-step explanation:

Confidence Interval = mean + or - Error margin (E)

mean = 37

sd = 10

n = 44

degree of freedom = n - 1 = 44 - 1 = 43

t-value corresponding to 43 degrees of freedom and 95% confidence level is 2.0165

E = t × sd/√n = 2.0165×10/√44 = 3.04

Lower limit = mean - E = 37 - 3.04 = 33.96

Upper limit = mean + E = 37 + 3.04 = 40.04

95% confidence interval is between 33.96 and 40.04

7 0

3 years ago

In a survey, 60% of interviewees say they like beach sports, while 55% like mountain sports. If 20% like both, what fraction of

My name is Ann [436]

Answer:

0.05

Step-by-step explanation:

To solve this problem, we first need to calculate the percentage of people that like beach or mountain sports.

This percentage can be calculated with the formula:

P(M or B) = P(M) + P(B) - P(M and B)

where:

P(M or M) is the percentage of people that like beach or mountain sports,

P(B) is the percentage of people that like beach sports,

P(M) is the percentage of people that like mountain sports,

P(B) is the percentage of people that like beach and mountain sports.

Then:

P(M or B) = 0.55 + 0.60 - 0.20 = 0.95

95% of the people like mountain or beach sport. Now, to find the percentage of people that like neither, we just need to make 1 minus the percentage of people that like beach or mountain sports:

P(Neither) = 1 - P(M or B) = 1 - 0.95 = 0.05

0.05 or 5% of the people interviewed like neither of these sports.

7 0

2 years ago

Read 2 more answers

write a function g whose graph represents a translation 2 units to the right followed by a horizontal stretch by a factor or 2 o

Alenkinab [10]

$\bf f(x)=&{{ A}}({{ B}}x+{{ C}})+{{ D}}
\\ \quad \\
y=&{{ A}}({{ B}}x+{{ C}})+{{ D}}
\\ \quad \\
f(x)=&{{ A}}\sqrt{{{ B}}x+{{ C}}}+{{ D}}
\\ \quad \\
f(x)=&{{ A}}(\mathbb{R})^{{{ B}}x+{{ C}}}+{{ D}}
\\ \quad \\
f(x)=&{{ A}} sin\left({{ B }}x+{{ C}} \right)+{{ D}}\\\\
f(x)=&{{ A}} \left|{{ B }}x+{{ C}} \right|+{{ D}}
\\\\
--------------------\\\\$

$\bf \bullet \textit{ stretches or shrinks horizontally by } {{ A}}\cdot {{ B}}\\\\
\bullet \textit{ flips it upside-down if }{{ A}}\textit{ is negative}\\
\left. \qquad \right. \textit{reflection over the x-axis}
\\\\
\bullet \textit{ flips it sideways if }{{ B}}\textit{ is negative}\\
\left. \qquad \right. \textit{reflection over the y-axis}$

$\bf \bullet \textit{ horizontal shift by }\frac{{{ C}}}{{{ B}}}\\
\left. \qquad \right. if\ \frac{{{ C}}}{{{ B}}}\textit{ is negative, to the right}\\\\
\left. \qquad \right. if\ \frac{{{ C}}}{{{ B}}}\textit{ is positive, to the left}\\\\
\bullet \textit{ vertical shift by }{{ D}}\\
\left. \qquad \right. if\ {{ D}}\textit{ is negative, downwards}\\\\
\left. \qquad \right. if\ {{ D}}\textit{ is positive, upwards}\\\\
\bullet \textit{ period of }\frac{2\pi }{{{ B}}}$

with that template in mind, let's see,

$\bf f(x)=|x| \implies \begin{array}{lllccll}
f(x)=&1|&1x&+0|&+0\\
&\uparrow &\uparrow &\uparrow &\uparrow \\
&A&B&C&D
\end{array}$

so, to shift it to the right by 2 units, simply set C = 2.
to stretch it by 2, set A = 1/2.

the smaller A is, the wider it opens, the larger it is, the more it shrinks.

5 0

3 years ago