Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

kaylala

  • 2 years ago

topic: PROVING IDENTITIES - help me please (SEE COMMENTS) (trigonometry)

  • This Question is Closed
  1. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @Loser66 help

  2. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    post your question please.

  3. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    ( Loser66 is offline )

  4. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    (1)/(sec x - tan x) = sec x + tan x

  5. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    i noticed

  6. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    \[\huge\color{blue}{ \frac{1}{\sec(x)-\tan(x)} =\sec(x)+\tan(x) } \]

  7. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    \[\huge\color{blue}{ 1 =(\sec(x)+\tan(x) )(\sec(x)-\tan(x))} \]

  8. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    I multiplied both sides times sec(40)-tan(40)

  9. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    why? is that possible? i thought we can only manipulate 1 side?

  10. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    shouldn't the other side be stable?

  11. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    Oh, then I take what I wrote back.

  12. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    okay

  13. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    \[\huge\color{blue}{ \frac{1}{\sec(x)-\tan(x)}=\sec(x)+\tan(x) } \] LEFT SIDE:\ top and bottom times sec(x)+tan(x) \[\huge\color{blue}{ \frac{\sec(x)-\tan(x)}{\sec^2(x)-\tan^2(x)}=\sec(x)+\tan(x) } \] Now, use the identity for the bottom, \[\sec^2x=\tan^2x+1\]

  14. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    Oh, the top should say + not - sorry.

  15. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    \[\huge\color{blue}{ \frac{\sec(x) \huge\color{red}{ + } \tan(x)}{\sec^2(x)-\tan^2(x)}=\sec(x)+\tan(x) } \]

  16. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    HUGE HINT: \[\sec^2x=\tan^2x+1~~~~~~~ther efore~~~~~\sec^2x-\tan^2x=1\]

  17. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    i do not get it. sorry

  18. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    Do you get what I did before. the last huge post in blue with a red plus ?

  19. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    nope but hey i found this: http://symbolab.com/solver/trigonometric-identity-calculator/prove%20%5Cfrac%7B1%7D%7B%5Csec(x)-%5Ctan(x)%7D%3D%5Csec(x)%2B%5Ctan(x) but the answer doesnt seem to be equal is there a way you could make it equal???

  20. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    Don't try to look it up else where, follow me. lets start over, ok? \[\huge\color{green} { \frac{1}{\sec(x)-\tan(x)}=\sec(x)+\tan(x) }\] I am working the left side: 1) Multiply top and bottom times sec(x)+tan(x)

  21. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok

  22. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    \[\color{green} { \frac{\sec(x)+\tan(x)}{(~~\sec(x)-\tan(x)~~)~(~~\sec(x)+\tan(x)~~)}=\sec(x)+\tan(x) }\] \[\color{green} { \frac{\sec(x)+\tan(x)}{\sec^2(x)-\tan^2(x)}=\sec(x)+\tan(x) }\] tell me if you don't get it.

  23. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    okay

  24. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    Now lets use an identity. \[\tan^2(x)+1=\sec^2(x)\] let's draw some conclusions. \[\tan^2(x)+1\color{blue} { -\tan^2(x) } =\sec^2x\color{blue} { -\tan^2(x) }\]\[1=\sec^2x-\tan^2x\] look at the denominator, what is it now equal to? has your identity been verified?

  25. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes. got it thanks @SolomonZelman

  26. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    You welcome, no problem, just knowing identities that's all the skill involved.

  27. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    and wow. that was shorter

  28. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    Yeah, I explained the same thing, but in a shorter way.

  29. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what's the technique?

  30. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    how come you're so good at this?

  31. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    what do you mean, the technique for what? Ohhh, I took trig last year, and got 97. I am just good at math and bad at other staff.

  32. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    technique in answering / proving these trigonometric identities? you did it so fast and in a shorter and much efficient way that's really cool WOW! Congratz! good for you

  33. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    Thank you! I am sure that if you try to do a lot of practice problems you will master them.

  34. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    i really hope so. failing trigonometry is the last thing that i'd want

  35. SolomonZelman
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 6

    WHAT?! FAILING?! what is your current grade may I ask ?

  36. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    last semester i got 2.0 in algebra now i'm taking trigonometry and it do is very hard. i dont have my grade yet since the 2nd semester just started.

  37. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    1 being the highest 3 - pass 5 - fail

  38. kaylala
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @SolomonZelman ^

  39. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.