Ask Experts Questions for FREE Help !
Ask
    pandalover123's Avatar
    pandalover123 Posts: 1, Reputation: 1
    New Member
     
    #1

    Jul 30, 2009, 06:12 AM
    Verifying Trig Identities
    how do you verify using identities

    (tanx+cotx)/cosx = secx
    ebaines's Avatar
    ebaines Posts: 12,131, Reputation: 1307
    Expert
     
    #2

    Jul 30, 2009, 08:32 AM
    Quote Originally Posted by pandalover123 View Post
    how do you verify using identities

    (tanx+cotx)/cosx = secx
    You have an error in your identity formula - please check it. Perhaps you mean this:

    (tanx + cotx)*sinx = secx

    Or maybe: (tanx + cotx)*cosx = cscx?

    Best way to approach these types of problems is to replace the tanx, cot, secx terms with the eqiuvalent sinx and cosx terms, then simplify. You'll find that you can then use basic identities like sin^2x + cos^2x = 1 to get it to work out.
    kapilagayan's Avatar
    kapilagayan Posts: 7, Reputation: 1
    New Member
     
    #3

    Jul 30, 2009, 09:10 AM
    Quote Originally Posted by ebaines View Post
    You have an error in your identity formula - plase checkit. Perhaps you mean this:

    (tanx + cotx)*sinx = secx

    Or maybe: (tanx + cotx)*cosx = cscx ??

    Best way to approach these types of problems is to replace the tanx, cot, secx terms with the eqiuvalent sinx and cosx terms, then simplify. You'll find that you can then use basic identities like sin^2x + cos^2x = 1 to get it to work out.
    :):)
    cnd822's Avatar
    cnd822 Posts: 1, Reputation: 1
    New Member
     
    #4

    Jan 22, 2011, 07:43 PM
    First you have to choose a side. I would choose the left because it's the most complicated. Substitute tangent for sine/cosine, and substitute cotangent for cosine/sine. So now you have (Sine/cosine) + (cosine/sine)all over cosine. You need to add the numerator together. To do this you need a LCD, which is sine multiplied by cosine. The new numerator is sine^2x + cos^2x. Substitute the numerator for one because that is what sine^2x + cos^2x is equivalent to. Then put that over the denominator of cosine. 1/cosine is the same thing as secant. It's the reciprocal relation. So they are equal.

Not your question? Ask your question View similar questions

 

Question Tools Search this Question
Search this Question:

Advanced Search


Check out some similar questions!

Verifying Trig Identities [ 2 Answers ]

secx-tanx=cosx/1+sinx

Verifying Trig Identities [ 1 Answers ]

sec^2X csc^2X=sec^2+csc^2X

Again verifying trig identities [ 5 Answers ]

I solved the first one I posted but the second one still gets me I can get to 2sin(X)cos(X)-(sin(X))/(cos(X))=(sin(X))/(cos(X))cos(2X) but I don't know which identity to use for cos(2X) in the left side. the original identity is sin(2X)-tan(X)=tan(X)cos(2X)

Verifying trig identities [ 3 Answers ]

Can someone help me with solving this identity? cotx = cscx + 1 ----- ----------- cscx - 1 cotx

Need to verifying Trig identities [ 5 Answers ]

I'm stuck! Can someone please help? I need to verify? tanx + cotx = 2tanx - cscx secx and


View more questions Search