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mathslover
 2 years ago
Basic trigonometry help needed.
mathslover
 2 years ago
Basic trigonometry help needed.

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mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1Prove : \(\sin (90  \theta) = \cos \theta\)

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1Actually I am confused that how can I : prove that sin in 2nd quadrant is +ve ? That is my basic confusion ...

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8can u use sin (AB) formula?

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1No idea. Actually that was just in start and the formula arises later, so I think that there must be an easier method?

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1:( not so good but OK ? :)

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1dw:1350046739720:dw nothing is there without naming , OK now I think.

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8dw:1350046691525:dw now find sin 90theta and cos theta using basic defination

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1In case of sin 90  theta , will perpendicular be : adjacent (base) and base will be opposite?

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8know the basic defination of sin and cos ? dw:1350046897401:dw apply it here, in terms of a and b,c

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1OH IT IS soh cah toa and not soa cah toa , sorry :(

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1sin = opposite / hypotenuse cos = adjacent / hypotenuse

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1sin (90theta) = b/c cos (theta) = b/c and hence sin(90theta) = cos(theta) , got it now? lol jk. Well is this right @hartnn

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1prove that sin in 2nd quadrant is +ve ? That is my basic confusion ...

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8here, put theta = theta

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8and use cos(theta) = cos theta

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1how to prove that cos(theta)=theta ?

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1again with the use of right triangle @hartnn ?

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8how will u find theta in triangle ?

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1oh yes .. silly me . So, a cartesian plane ?

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1no, cartesian plane will not work also.

sara12345
 2 years ago
Best ResponseYou've already chosen the best response.1ccw : +ve angle cw : ve angle

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8because lengths will be positive , so ratio will always come out to be positive, hence, maybe cartesian plane won't work

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1searched net now, http://www.mathsisfun.com/algebra/trigfourquadrants.html is that the correct one ?

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8yes, its correct....we could prove it using coordinates.... (cos t,sin t)= (x,y) so sin t is +ve in 2nd quadrant

mathslover
 2 years ago
Best ResponseYou've already chosen the best response.1doubts ended :) thanks a lo.

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8mathisfun is always a nice reference....

sara12345
 2 years ago
Best ResponseYou've already chosen the best response.1more we knw more confuse we become

hartnn
 2 years ago
Best ResponseYou've already chosen the best response.8more we practice, more the confusion vanishes....

sara12345
 2 years ago
Best ResponseYou've already chosen the best response.1more we practice, more ways we look at things n hence more confusions which ofcourse gives kick ;p
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