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# Trigonometry watch

1. How would I find the integral of √5cos(2x - λ) - 1 ?
2. (Original post by znx)
How would I find the integral of √5cos(2x - λ) - 1 ?

For the first integral, you can do it without much thinking. Though if you really must, use the sub
3. (Original post by RDKGames)

For the first integral, you can do it without much thinking. Though if you really must, use the sub
I got (√5/2)sin(2x - λ) - x, so Im supposed to show that when I evaluate it with upper bound λ and lower bound 0, the area is 2 - λ. I cant seem to get the right answer? I thought maybe I had the wrong integral but im not sure now.
4. (Original post by znx)
I got (√5/2)sin(2x - λ) - x, so Im supposed to show that when I evaluate it with upper bound λ and lower bound 0, the area is 2 - λ. I cant seem to get the right answer? I thought maybe I had the wrong integral but im not sure now.
Yeah you're not getting that answer from
5. (Original post by RDKGames)
Yeah you're not getting that answer from
Oh right, the original equation is f(x) = 2(2cosx - sinx)sinx.
If I integrated that would It come out as 2 - λ?
6. (Original post by znx)
Oh right, the original equation is f(x) = 2(2cosx - sinx)sinx.
If I integrated that would It come out as 2 - λ?
Nope

What's the FULL question that you're attempting to do here?
7. QUOTE=RDKGames;76291558]Nope

What's the FULL question that you're attempting to do here?[/QUOTE]

Its part iv)
8. (Original post by znx)
Its part iv)
You need to use the fact that and deduce the exact value of before substituting it into

EDIT: You actually find it in part (i) anyway so use it.
9. (Original post by RDKGames)
You need to use the fact that and deduce the exact value of before substituting it into

EDIT: You actually find it in part (i) anyway so use it.
With the integral what happened to the 1/2 in √5/2?
10. (Original post by znx)
With the integral what happened to the 1/2 in √5/2?
Do the integral. You should end up with from the lower bound. Use the fact that so then you just have from the lower bound. The half shall then cancel accordingly.
11. (Original post by RDKGames)
Do the integral. You should end up with from the lower bound. Use the fact that so then you just have from the lower bound. The half shall then cancel accordingly.
Thank you for taking the time to help, I really appreciate it mate.

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Updated: February 25, 2018
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