Talking about a subject with a friend just loud enough so that the boy/girl on the other table starts talking about the same subject with his/her friend, then proceeding to impress eachother with your copious knowledge of said subject whilst making the occasional eye contact.
Friend of girl: I need to solve
sin(ax)sin(bx) - k cos(ax)cos(bx) = -1
where k > 1 is constant and so are a and b, and they are all irrational.
Girl: *notices boy so increases volume* Well, you could rewrite the left-hand side as:
\frac{1}{2}(\cos(ax-bx)-\cos(ax+bx))-\frac{k}{2}(\cos(ax+bx)+\cos(ax-bx))=-1
Boy: *to his friend, speaking loudly to impress girl* For the original equation:\sin (ax)\cdot\sin (bx) - k\cdot \cos (ax) \cos (bx) = 5
Girl: and sin(ax)sin(bx) - kcos(ax)cos(bx) + 1 = 10
Boy: and sin(bx) - kcsc(ax)cos(bx) + cot(ax) = 0
Girl: Which can be simplified to sin = 1
*Girl and Boy smile at each other*
Friend of girl to friend of boy: They're totally having study sex.
sin(ax)sin(bx) - k cos(ax)cos(bx) = -1
where k > 1 is constant and so are a and b, and they are all irrational.
Girl: *notices boy so increases volume* Well, you could rewrite the left-hand side as:
\frac{1}{2}(\cos(ax-bx)-\cos(ax+bx))-\frac{k}{2}(\cos(ax+bx)+\cos(ax-bx))=-1
Boy: *to his friend, speaking loudly to impress girl* For the original equation:\sin (ax)\cdot\sin (bx) - k\cdot \cos (ax) \cos (bx) = 5
Girl: and sin(ax)sin(bx) - kcos(ax)cos(bx) + 1 = 10
Boy: and sin(bx) - kcsc(ax)cos(bx) + cot(ax) = 0
Girl: Which can be simplified to sin = 1
*Girl and Boy smile at each other*
Friend of girl to friend of boy: They're totally having study sex.
by carlieyvonnem October 21, 2009