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Vesnalui [34]
3 years ago
13

If costheta=4/5 then what is sec^2theta

Mathematics
1 answer:
DaniilM [7]3 years ago
5 0

Answer:

\sec^2(\theta)=\frac{25}{16}

Step-by-step explanation:

Recall what the relationship between cosine and secant:

\sec(\theta)=\frac{1}{\cos(\theta)}

In other words, secant is the reciprocal of cosine.

So, if we know cosine, we only need to find its reciprocal to find secant.

We are given that cosine is:

\cos(\theta)=\frac{4}{5}

Then secant must be:

\sec(\theta)=\frac{5}{4}

So:

\sec^2(\theta)=(\frac{5}{4})^2

Square:

\sec^2(\theta)=\frac{25}{16}

And we're done!

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Sally builds these steps for her dog.what is the volume of the steps
777dan777 [17]

Answer:

300 we just finished the test...

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
How do you solve this problem?
jekas [21]
Very nice problem. You should look up the history of this question. It has a very long one having to do with mirrors made between 50 BC and 50 AD.

Step One
Find AB, BC, AC
Before beginning this problem, I'm going to arbitrarily name 
c = AB
a = BC
b = AC It just makes the calculations easier.

AB = radius of the large circle - radius of the medium circle = 20.62 - 8.04 = 12.58
BC = Radii of the two smaller circles added together = 8.04 + 7.35 = 15.39
AC = Radius of the large circle - Radius of the small circle = 20.62 - 7.35 = 13.27

So
a = 15.39
b = 13.27
c = 12.58

Step Two
Find Angle A or <BAC
a^2 = b^2 + c^2 - 2*b*c * Cos(A)
15.39^2 = 12.58^2 + 13.27^2 - 2 * 12.58 * 13.27 * Cos(A)
236.852 = 158.26 + 176.1 -  333.87 * Cos(A)
236.852 = 334.4 - 333.87*Cos(A)
-97.55 = - 333.87 *  Cos(A) 
-97.55 / -333.87 = Cos(A)
0.2922 = cos(A)
A = cos-1(0.2922)
A = 73.01 degrees

Step Three
Just to see if you understand what was done, I'll give you the givens for finding c, and the answer and you can work through the calculations to see if your answer agrees with mine. If it doesn't PM me.
c = 12.58
b = 13.27
a = 15.39

12.58^2 = 13.27^2 + 15.39^2 - 2*13.27*15.39*Cos(C)
C = 51.42

Step Four
Find <B
Every triangle has 180 degrees so
B = 180 - <A - C
B = 180 - 51.42 - 74.01
B = <54.57. 
I have found a moderator who opened the question up so that I can show you why the Cos law is the only way to do this. If the circles are very disproportionate as in this diagram, then no simple assumption can be made. The cos law is all that will work. I would have posted this earlier, but I didn't think anyone would find another method. It's ingenious but not possible for the situation below.

3 0
3 years ago
Deane is flying to a destination that is 2745 miles away. The plane's average speed is 450 mph. Write the slope-intercept form o
Dmitriy789 [7]
The equation in y = mx+b form is y = -450x+2745

where,
x = number of hours that have passed by
y = distance to destination in miles

The y intercept is 2745 since this is the initial starting y value, aka the starting distance. Therefore b = 2745.

The slope is -450 or -450/1 since for each hour, the distance goes down by 450. You can think of it as
slope = (change in y)/(change in x)
slope = (change in distance)/(change in time)
slope = (-450 miles)/(1 hour)
slope = -450
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3 years ago
How many does 95 fit into 1660
nadezda [96]
17.4736843 or 17 remainder 45
3 0
3 years ago
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katie pays $725 a month for rent, $40 for cable and $3.60 an hour for local telephone service. if his monthly expenditures last
Nuetrik [128]
The answer would be: He spent 17 hours on the phone
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8 0
2 years ago
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