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•  » I need some help, all the way back here in Sweden. Easy stuff, I guess

## #1 2006-04-21 19:04:10

Zzulu
Guest

### I need some help, all the way back here in Sweden. Easy stuff, I guess

I'll try to translate these questions to the best of my ability, since it's originally written in Swedish. (there's a distinct lack of online math discussion over here for some reason) I have 2 questions in total.

Here it goes;

1- I have to calculate the exact value of sin(105). How do I do that?

2- I need to calculate the "area" between these two f(t)=13t-5t^2 and f(t)= 1/2t

All help is appreciated!

## #2 2006-04-21 19:30:49

ganesh
Moderator

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### Re: I need some help, all the way back here in Sweden. Easy stuff, I guess

Zzulu,
Sin(A+B)=SinACosB+CosASinB
Sin(105)=Sin(60+45)=Sin60Cos45+Cos60Sin45
We know, sin60=√3/2, cos45=1/√2, cos60=1/2, sin45=1/√2
Therefore, Sin(105)=√3/2√2+1/2√2= (√3+1)/2√2
= (approximately) 0.9659

Character is who you are when no one is looking.
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