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Nana76 [90]
2 years ago
15

Which of the following in an identity?

Mathematics
1 answer:
sammy [17]2 years ago
5 0
By "which is an identity" they just mean "which trigonometric equation is true?"

What you have to do is take one of these and sort it out to an identity you know is true, or...

*FYI: You can always test identites like this:
Use the short angle of a 3-4-5 triangle, which would have these trig ratios:
sinx = 3/5    cscx = 5/3
cosx = 4/5   secx = 5/4
tanx = 4/3    cotx = 3/4
Then just plug them in and see if it works. If it doesn't, it can't be an identity!

Let's start with c, just because it seems obvious.
The Pythagorean identity states that sin²x + cos²x = 1, so this same statement with a minus is obviously not true.

Next would be d. csc²x + cot²x = 1 is not true because of a similar Pythagorean identity 1 + cot²x = csc²x. (if you need help remembering these identites, do yourslef a favor and search up the Magic Hexagon.)

Next is b. Here we have (cscx + cotx)² = 1. Let's take the square root of each side...cscx + cotx = 1. Now you should be able to see why this can't work as a Pythagorean Identity. There's always that test we can do for verification...5/3 + 3/4 ≠ 1, nor is (5/3 +  3/4)².

By process of elimination, a must be true. You can test w/ our example ratios:
sin²xsec²x+1 = tan²xcsc²x
(3/5)²(5/4)²+1 = (4/5)²(5/3)²
(9/25)(25/16)+1 = (16/25)(25/9)
(225/400)+1 = (400/225)
(9/16)+1 = (16/9)
(81/144)+1 = (256/144)
(81/144)+(144/144) = (256/144)
(256/144) = (256/144)
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Step-by-step explanation:

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7 0
2 years ago
Jackson is three times as heavy as Andrew. If the sum of their weight is 360 pounds, find Andrews weight​
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3 years ago
Read 2 more answers
Urgent please help!!
wolverine [178]

Answer:

i think it would be B because if AC= 80 and thats like the distane between then abc would be 80 if im thinking right

Step-by-step explanation:

but  hey if im wrong ill have my friend punch me in the arm to make it even

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2 years ago
PLS HELP WILL GIVE BRAINLIEST
Oduvanchick [21]

Answer:

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The angle acute so my guess is 60

Hope this helps :)

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2n -4

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