Exact Trig Values - Hand Trick | Trigonometry | Maths | FuseSchool Video Lecture - Class 8

[Music]
hi I'm Lucy and in this second part
video I'm going to show you a hand trick
to find it exact trig values that you
need to know so the angle from part 1
with 0 30 45 60 and 90 we're going to
use those same angles so different
tricks this time rather than that table
of values take either hands with your
palms facing towards you and label your
little finger at 0 degrees your ring
finger is 30 middle one is 45 60 and
your son is 90 degrees to make this work
you just need to remember the square
root the number of fingers and divide by
2 if we wanted sine 30 we'd spend down
our 30-degree finger and you just have
your baby finger underneath so sine 30
is square root 1/2 because there's only
one finger underneath which simplifies
to 1/2 if we wanted sine 90 degrees it's
bend down your 90 degrees thumb and so
you have 4 fingers underneath so sine 90
is square root of 4 divided by 2 which
simplifies to 1
lauric sine 60 be black are the answer
and click here when you're ready to
check
did you get square root 3/2 because we
just can't a finger above instead of the
ones below so 4 cos 60 bend down your 60
finger and count the fingers above 1 the
code 60 is square root 1 divided by 2
which simplifies to 1/2
well of course 9tv
wipe out the answer and click here when
you're ready to chat
did you get zero degrees spend on your
90 degree song and there are no fingers
above the root zero divided by 2 is zero
I'm finally pan the pan we still count
fingers but there is just one extra
little twist the same as the sine and
cos send down the angle finger
so let's find x 60 that's been done our
60 degree finger we've got one cosine
finger above and three sine fingers
below the tan we flip our hand over and
we have three time fingers above and the
one cosine below so tan it's square root
fingers over square root fingers this
square root 3 over square root 1
we're simplified to retreat what would
turns out to be
work out the answer and click here when
you're ready to clap
did you get square root 1 divided by
square root 3 which is simplified to 1
over root 3 there we have a really easy
way of remembering those exact values we
use our hand special angles 0 30 45 50
and 90 and just remember the signing
cause it's three fingers divided by 2
sine is root fingers to low the best
finger and cause it's written above the
best finger and the tan you just flip it
over and it's rich fingers divided by
brute fingers