Proving $ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $
$begingroup$
I am currently working on understanding trig identities.
A question has me stumped, and no matter how I look at it, it never leads to the proof. I believe I am making a mistake when dividing multiple fractions.
$$ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $$
For my first step I break up the $csc x$ and $cot x$ in the numerator and add them together to make:
$$frac{frac{1+cos x}{sin xcos x}}{tan x+sin x}$$
I then simplify further and end up at:
$$ frac{cos x+cos^2 x}{sin^2 xcos^2 x} $$
From here on I don't see any identities, or possible ways to decompose this further.
trigonometry problem-solving
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add a comment |
$begingroup$
I am currently working on understanding trig identities.
A question has me stumped, and no matter how I look at it, it never leads to the proof. I believe I am making a mistake when dividing multiple fractions.
$$ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $$
For my first step I break up the $csc x$ and $cot x$ in the numerator and add them together to make:
$$frac{frac{1+cos x}{sin xcos x}}{tan x+sin x}$$
I then simplify further and end up at:
$$ frac{cos x+cos^2 x}{sin^2 xcos^2 x} $$
From here on I don't see any identities, or possible ways to decompose this further.
trigonometry problem-solving
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2
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Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
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– Chaitanya Tappu
Nov 30 '18 at 2:29
add a comment |
$begingroup$
I am currently working on understanding trig identities.
A question has me stumped, and no matter how I look at it, it never leads to the proof. I believe I am making a mistake when dividing multiple fractions.
$$ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $$
For my first step I break up the $csc x$ and $cot x$ in the numerator and add them together to make:
$$frac{frac{1+cos x}{sin xcos x}}{tan x+sin x}$$
I then simplify further and end up at:
$$ frac{cos x+cos^2 x}{sin^2 xcos^2 x} $$
From here on I don't see any identities, or possible ways to decompose this further.
trigonometry problem-solving
$endgroup$
I am currently working on understanding trig identities.
A question has me stumped, and no matter how I look at it, it never leads to the proof. I believe I am making a mistake when dividing multiple fractions.
$$ frac{csc x + cot x}{tan x + sin x} = cot xcsc x $$
For my first step I break up the $csc x$ and $cot x$ in the numerator and add them together to make:
$$frac{frac{1+cos x}{sin xcos x}}{tan x+sin x}$$
I then simplify further and end up at:
$$ frac{cos x+cos^2 x}{sin^2 xcos^2 x} $$
From here on I don't see any identities, or possible ways to decompose this further.
trigonometry problem-solving
trigonometry problem-solving
edited Nov 30 '18 at 5:06
Blue
48.4k870154
48.4k870154
asked Nov 30 '18 at 2:20
Rawley FowlerRawley Fowler
47116
47116
2
$begingroup$
Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
$endgroup$
– Chaitanya Tappu
Nov 30 '18 at 2:29
add a comment |
2
$begingroup$
Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
$endgroup$
– Chaitanya Tappu
Nov 30 '18 at 2:29
2
2
$begingroup$
Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
$endgroup$
– Chaitanya Tappu
Nov 30 '18 at 2:29
$begingroup$
Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
$endgroup$
– Chaitanya Tappu
Nov 30 '18 at 2:29
add a comment |
2 Answers
2
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$begingroup$
$require{cancel}$
As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.
$$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
$$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$
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1
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you beat me to it. (+1)
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– clathratus
Nov 30 '18 at 2:37
add a comment |
$begingroup$
$$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$
$tan x=dfrac1?,sin x=dfrac1?$
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add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
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votes
$begingroup$
$require{cancel}$
As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.
$$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
$$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$
$endgroup$
1
$begingroup$
you beat me to it. (+1)
$endgroup$
– clathratus
Nov 30 '18 at 2:37
add a comment |
$begingroup$
$require{cancel}$
As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.
$$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
$$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$
$endgroup$
1
$begingroup$
you beat me to it. (+1)
$endgroup$
– clathratus
Nov 30 '18 at 2:37
add a comment |
$begingroup$
$require{cancel}$
As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.
$$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
$$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$
$endgroup$
$require{cancel}$
As Chaitanya Tappu noted, you made a mistake when adding $csc x$ and $cot x$.
$$frac{csc x+cot x}{tan x+sin x}=frac{frac{1}{sin x}+frac{cos }{sin x}}{frac{sin x}{cos x}+frac{sin xcos x}{cos x}}=frac{frac{1+cos x}{sin x}}{frac{sin x(1+cos x)}{cos x}}=frac{cancel{1+cos x}}{sin x}cdotfrac{cos x}{sin xcancel{(1+cos x)}}$$
$$=frac{cos x}{sin x}cdotfrac{1}{sin x}=cot xcsc x$$
edited Dec 7 '18 at 12:42
answered Nov 30 '18 at 2:34
Robert HowardRobert Howard
1,9261822
1,9261822
1
$begingroup$
you beat me to it. (+1)
$endgroup$
– clathratus
Nov 30 '18 at 2:37
add a comment |
1
$begingroup$
you beat me to it. (+1)
$endgroup$
– clathratus
Nov 30 '18 at 2:37
1
1
$begingroup$
you beat me to it. (+1)
$endgroup$
– clathratus
Nov 30 '18 at 2:37
$begingroup$
you beat me to it. (+1)
$endgroup$
– clathratus
Nov 30 '18 at 2:37
add a comment |
$begingroup$
$$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$
$tan x=dfrac1?,sin x=dfrac1?$
$endgroup$
add a comment |
$begingroup$
$$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$
$tan x=dfrac1?,sin x=dfrac1?$
$endgroup$
add a comment |
$begingroup$
$$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$
$tan x=dfrac1?,sin x=dfrac1?$
$endgroup$
$$dfrac{a+b}{dfrac1a+dfrac1b}=cdots=ab$$ for $a+bne0$
$tan x=dfrac1?,sin x=dfrac1?$
answered Nov 30 '18 at 3:52
lab bhattacharjeelab bhattacharjee
225k15157275
225k15157275
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2
$begingroup$
Note that $csc x + cot x = dfrac{1}{sin x} + dfrac{cos x}{sin x} = dfrac{1 + cos x}{sin x}$
$endgroup$
– Chaitanya Tappu
Nov 30 '18 at 2:29