Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


Math Forum
»
Discussions
»
Inactive
»
k12.ed.math
Notice: We are no longer accepting new posts, but the forums will continue to be readable.
Topic:
Trigonometry
Replies:
4
Last Post:
Dec 8, 2004 1:04 AM




Re: Trigonometry
Posted:
Dec 3, 2004 3:20 AM


"Jason" <jasonpush@hotmail.com> wrote in message <a href="news://es5vq0p1hld42fjm5o319h0b32vcd9kf2o@4ax.com...">news://es5vq0p1hld42fjm5o319h0b32vcd9kf2o@4ax.com...</a> > If sin x = 1/3 and pi/2 < X < 2pi > Find: > > (i) tan x > > (ii) cos x > > therefore x is in the 3rd quadrant as sin x = 1/3 = O/H (+) > > so as per pythag if a^2 = b^2 + c^2 then c^2 = a^2  b^2 = > > 3^2  1^2 = 8 so sqrt of 8 approx= 2.83, so tan = O/A = 1/2.83 and > > cos = A/H = 2.83/3 > > > is this correct? > > Thank you > > Jason
Looks good to me, except if you are going to approximate the square root of 8, why not estimate tan x as 0.35 and cos x as .94. Otherwise, write them in terms of the square root of x, tan x = sqrt(8)/8 and cos x = sqrt(8)/3.
Aaron
 submissions: post to k12.ed.math or email to k12math@k12groups.org private email to the k12.ed.math moderator: kemmoderator@k12groups.org newsgroup website: <a href="http://www.thinkspot.net/k12math/">http://www.thinkspot.net/k12math/</a> newsgroup charter: <a href="http://www.thinkspot.net/k12math/charter.html">http://www.thinkspot.net/k12math/charter.html</a>



