[PartyPaint]

BRAIN TEASER
Hey guys, I thought about a little thread for some smart guys.
I'll post every day a new "brain teaser" and the winner of the day
get's +rep.

Rules
-no questions. send me pm.
-only 1 reply per "brain teaser"
-only 1 answer per "brain teaser"

Let's start with something simple.
Solve this:

Code:

1+1+1+1+1+1+1-1+1+1+1-1+1+1+1+1+1x1+1+1+1+1-1+1+1+1+1

[narc0tics]

I like the idea behind this!

My guess would be 20.

[Frooxius]

It's 20.
You call that a teaser? :lol: Just simple math :3

[PartyPaint]

It's 20.
You call that a teaser? :lol: Just simple math :3

Yay, we have a winner. That was just an easy example.
I think about somthin difficult till tomorrow. (:

[1llusion]

20

=,= didn't see that coming... too late I guess =,=

[whitewolf]

it sounds fun to me...i want to try guessing ur teaser

[whitewolf]

it sounds fun to me...i want to try guessing ur teaser

[Shining White]

Sin45+Cos90/tan45 = ????

one from me ( for begin )

[Shining White]

Sin45+Cos90/tan45 = ????

one from me ( for begin )

[Frooxius]

Shining White Holmse: Pfff, that's simple Though you forgot to specify if the values are degrees or radians, but judging from the values, they're degrees.

The result is:
sqrt(0.5) which is approximately 0,70710678118654752440084436210485

That's because it's the cos(90°)/tan(45°) results in zero, because cos(90°) is zero, so only sin(45°) is needed to calculate.

If you use a right triangle with hypotenuse length equal to 1 and with angle 45°, then two remaining sides are equal. Therefore:
c = 1
a = b = ?
Sides a and b represent sin(45°) and cos(45°) so
a = b = sin(45°) = cos(45°) = d

And from the Pythagorean we know that
c^2 = a^2 + b^2
Which is
1^2 = sin(45°)^2 + cos(45°)^2
But we know that they're equal so we can do this:
1 = d^2 + d^2
Which is
1 = 2(d^2)
And we need to know d, which equals both to sin(45°) and cos(45°), so we extract it:
1/2 = d^2
sqrt(1/2) = d
So we get
d = sqrt(0.5)
And we substituted sin(45°) with d so the final result is:
sin(45°) = sqrt(0.5)