Caculus Help : Integrating with trig identities?

In summary, the conversation revolved around integrating sin (2x)/(1+sinx) and the use of trigonometric identities to solve it. The problem was eventually solved by replacing sin (2x) with 2 sin x cos x and using the substitution method.
  • #1
eay444
5
0

Homework Statement



integrate: sin (2x)/(1+sinx)



Homework Equations



(sin x)^2 + (cos x) ^2 = 1
sin (2x) = 2 sin x cos x
cos (2x) = (cos x)^2 - (sin x)^2



The Attempt at a Solution



I've been trying to integrate this thing for about an hour by rearranging various trig idenities with no luck. Am I missing something? I don't think this problem is supposed to be that hard. Someone please help!
 
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  • #2
I would try first replacing sin (2x) with 2 sin x cos x then do u sub and let u = cos x. Try that and see if it helps
 
  • #3
I got it now, Thanks for your help.
 

FAQ: Caculus Help : Integrating with trig identities?

What is the purpose of integrating with trig identities in calculus?

Integrating with trig identities in calculus allows us to solve more complex integration problems involving trigonometric functions. It also helps us simplify integrals and make them easier to solve.

How do I identify which trig identity to use when integrating?

The key to identifying which trig identity to use when integrating is to look for patterns and similarities between the integral and the trigonometric functions. You can also consult a list of commonly used trig identities to help you determine the appropriate one to use.

Can I use any trig identity when integrating?

Yes, you can use any trig identity when integrating as long as it helps you simplify the integral and make it easier to solve. However, it is important to check the validity of the identity and ensure that it is applicable to the specific problem at hand.

What are some common mistakes to avoid when integrating with trig identities?

Some common mistakes to avoid when integrating with trig identities include using the wrong identity, making algebraic errors, and forgetting to include the constant of integration. It is important to carefully check your work and double-check your steps to avoid these mistakes.

Are there any tips for effectively integrating with trig identities?

One tip for effectively integrating with trig identities is to practice and become familiar with commonly used identities. It is also helpful to break down the integral into smaller parts and apply the appropriate identity to each part. Additionally, always remember to check your work and simplify as much as possible before moving on to the next step.

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