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Trig problem

  • Thread starter Complexity
  • Start date
  • #1
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Homework Statement



(Cos[x]^2) (Tan[x] + Cot[x]) Simplify the equation by hand!!

Homework Equations





The Attempt at a Solution



cos^2 / (tan + cot)
cos^2 / (sin/cos + cos/sin) * sin*cos/(sin*cos)
sin*cos^3 / (sin^2 + cos^2)
sin*cos^3 / 1
sin(x) * cos^3(x)

this is wrong b/c i divided it...

NVM found the answer:

(cos^2(x))(sin(x)/cos(x) + cos(x)/sin(x))
cos(x)sin(x) + cos^3(x)/sin(x)
cos(x)sin(x) + cos^2(x)cos(x)/sin(x)
cos(x)sin(x) + (1 - sin^2(x))cos(x)/sin(x)
cos(x)sin(x) + (cos(x) - sin^2(x)cos(x))/sin(x)
cos(x)sin(x) + cot(x) - sin(x)cos(x)
cot(x)
 
Last edited:

Answers and Replies

  • #2
Mentallic
Homework Helper
3,798
94
Sorry, it's wrong because you divided what?

[tex]\frac{cos^2x}{tanx+cotx}\equiv sinx. cos^3x[/tex]

The question says simplify [tex]cos^2x(tanx+cotx)[/tex]. Was this a typo?
 
  • #3
Mentallic
Homework Helper
3,798
94
It's hard to read what you've done... And I can tell you now that it's not equivalent to cot(x).
 
  • #4
24
0
I get cot(x) as well, though you can skip quite a few steps in the simplification.
Graphing confirms these are equivalent.
 

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