Basic Trigonometry table trick - Introduction to Trignometry Video Lecture - Class 10

well it's just you just you need to
remember for there will be five
different digits five basic digits with
which you can drive your whole table
from four zero to 90 degrees for whole
for all the trigonometric identities
which are sine cosine tangent cosecant
and cotangent now let me let me show you
the simple technique for that first you
need to write that the values from 0 to
4 which is 0 1 2 3 & 4 now we have as we
have ended at 4 just divide every digit
with 4 so you can get it 4 4 4 4 4 now
take the square root of all the digits
what you have written here now this is
what I call a basic values basic values
for our trigonometric table now instead
of now what I want you to know is the
basic thing as I told you don't need to
remember you don't need to remember any
many things instead just remember 0 2 4
now what we are looking for the basic
values for the tan basic value in the in
basic values of trigonometric table now
let's say let us write for the 0 degrees
30 degrees 45 degrees 60 degrees and 90
degrees now create a table for that so
that you can get appropriate values at
any time
here is our table now for what values
for what identities which you are
looking for sine theta cos theta tan
theta cotangent secant cosecant now
first thing which I want you to know is
just use the first let us perform the
first sequence on the first digit which
we have derived before which is like 0
over 4 1 over 4 2 or 4 3 or 4 and 404 as
we know 0 over 4 will give us 0 and the
square root of 0 is again 0 so hcq I can
ride it back and 1 over 4 will give us 1
over 2 root 2 over 2 we know that
cancellation of 2 & 4 will give us 1
over 2 1 over root 2 X cubed for that
and finally we know the square root of 4
is 2 and square root we don't have that
we don't have exact value for a square
root 3 so we can just write it as square
root over 2 3 over 2 and finally we can
cancel out so 4 and we get square root 1
which is ultimately 1 now once we got
the first line I must say that you have
dragged the whole table you might be
wondering how I am saying that because
by using the basic trigonometric
identities I will let you understand the
whole table which derive from the first
slide now since we know the sine and
cosine are opposite by 90 degrees so
just flip all the values from from 90 to
0 62 30 45 45 30 to 60 0 to 0 so instead
just write from the left to right it's
like 1 root 3 over 2 1 over root 2 1
over 2 finally 0 now to get this tan
theta values just we know we should
remember that basic trigonometric
identity which is sine theta over cos
theta
which gives you tan-theta right so one
over so if you want to know let's stop
than zero so you can write it as sine 0
or cos 0 which gives you the tan 0 and
sine 0 is 0 cos 0 is 1 1 over 0 it will
give you 0 similarly 1 over 2 root 3
over 2 will 2 to get cancer will give
you 1 over root 3 similarly root 2 1
over root 2 1 over 2 get cancelled will
give you 1 and 5 and once again what
through the dinner to at the denominator
get cancelled you get left with 2 3
finally 1 over 0 which you know which is
infinity now again since we know that
trigonometric identities tan theta equal
to 1 over quote theta instead of writing
every value inverse of it just use the
basic technique which I told you before
for the sign write further do for the
thing do same thing for the tan right
from the left from the right to the left
it's like infinity root 3 1 1 over root
3 finally 0 now we left with two basic
to 2 identities of trigonometry as I
told you before that you don't need to
remember even a single digit instead
just use the basic 5 digits which is 0
to 4 now first we can we know the basic
identity of secant theta is over 1 over
cos theta all right so cos theta 1 over
course is 1 over 1 give you 1 1 over
root 3 over 2 will give you 2 over root
3 1 over root 2 will give you root 2 1
over 2 will give you 2 1 over 0 will
give you infinity now again use the same
basic technique just write even a
reverse order so that you will get the
values of that with 2 3 2 right 2 over
root 3 and finally 1 here you got the
whole table with none other than the
basic 5 digits from 0 to 4 hope you got
hope you guys like this thing if you
should really like the
and if you want me to do something else
let's write some comments