Question

a math question

Answer 1

\[\cos ^{-1}(\sin \frac{ 11\pi }{ 6 })\]

Answer 2

@satellite73

Answer 3

@satellite73 plz help

Answer 4

Play with the values for this one...
Let
\[x = \cos^{-1}(\sin \frac{11\pi}{6})\]and if we get the cosine of both sides, we are left with...\[\cos x = \sin \frac{11\pi}{6}\]perhaps it's simpler from here on in?

Answer 5

the answer is 2pi/3 ??

Answer 6

seems like it

Answer 7

@satellite73

Answer 8

You're right.
Hang on...
in general,
\[\cos(\frac{\pi}{2} - \theta)=\sin(\theta)\]
So
\[\sin\frac{11\pi}{6}=\cos \left( \frac{\pi}{2}-\frac{11\pi}{6} \right)\]
\[=\cos \left( -\frac{8\pi}{6} \right)\]
It would appear
\[x=-\frac{4\pi}{3}+2k\pi\] where k is any integer.
But since we're talking angles, adding 360 degrees, or 2pi, would give the same angle. Consider doing that here, because that negative angle ain't pretty XD

\[x = -\frac{4\pi}{3}+2\pi=\frac{2\pi}{3}\]

Answer 9

k thanks but this other one is hard \[\tan(\sin ^{-1}-\frac{ 5 }{ 13 }\]

Answer 10

)

Answer 11

It's a bit complicated, but think of it this way... the SINE of the angle is -5/13, so what is its TANGENT?

Answer 12

here's what you do: sine of what angle will equal 5/13? Then you take that angle and take the tan of it.

Answer 13

but i how do i do that?

Answer 14

answer is 5/12 by the way