Ask Experts Questions for FREE Help !
Ask
    liang11's Avatar
    liang11 Posts: 4, Reputation: 1
    New Member
    		  
    #1

    Jul 24, 2009, 11:28 PM
    trigonometric equations
    Prove (Sin5A - Sin4A)/(Cos4A + Cos5A) = Tan A/2
    Unknown008's Avatar
    Unknown008 Posts: 8,076, Reputation: 723
    Uber Member
    		  
    #2

    Jul 25, 2009, 01:33 AM

    Convert all the '5A' and '4A' into simple angles, then half angles.
    liang11's Avatar
    liang11 Posts: 4, Reputation: 1
    New Member
    		  
    #3

    Jul 25, 2009, 09:23 PM
    Quote Originally Posted by unknown008 View Post
    convert all the '5a' and '4a' into simple angles, then half angles.





    i still don't understand... do u have the solutions?
    tej pratap sing's Avatar
    tej pratap sing Posts: 11, Reputation: -2
    New Member
    		  
    #4

    Jul 26, 2009, 12:43 AM
    Quote Originally Posted by liang11 View Post
    i still don't understand...do u have the solutions?
    cos(A+B)=cosAcosB-sinAsinB
    tej pratap sing's Avatar
    tej pratap sing Posts: 11, Reputation: -2
    New Member
    		  
    #5

    Jul 26, 2009, 11:53 AM

    sinC-sinD=2cosC+D/2 . SinC-D/2
    cosC+cosD=2cosC+D/2 . CosC-D/2
    apply this formula in question i.e
    sin5A-sin4A 2cos9A/2 .sinA/2 sinA/2
    -------------- = --------------------- = --------- = tanA/2
    cos4A+cos5A 2cos9A/2 . CosA/2 cosA/2
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

To prove trigonometric equations [ 3 Answers ]

Could you please solve this problem? (cotA + CosecA - 1)/(cotA-cosecA+1) =(1+cosA)/sinA I have to prove that LHS = RHS.

Trigonometric Equations [ 1 Answers ]

Determine the solutions for (1+secx) / (secx) = (sin^2x) / (1-cosx) in the interbal x E (-2pi, 2pi)

Trigonometric Equations [ 2 Answers ]

Hi all, I'm just new to this site. Looking a bit of help with my nightmare Analytical methods assignmnet on trigonometric equations :mad: Just need a bit of direction to get me on the right track with solving these for 0-360 degrees: 4-7sin(x)=0 15sin^2(A)+sin(A)-2=0 I also have to...

Solving Trigonometric Equations [ 1 Answers ]

solve: 3sin^2x-cos^2x=0 4sin^2x-3=0

Solving trigonometric equations [ 1 Answers ]

Prove: sin^3 X+cos^4 X=1 Here is what I have done so far: Prrof: sin^3x+cos^4x=1 sin^3x=1-cos^4x sin^3x=(1-cos^2x)(1+cos^2x) sin^3x=sin^2x(1+cos^2x) sin^3x-=0

View more questions Search