Posted by Joel on November 01, 2002 at 18:15:39:
In Reply to: i dun get it... posted by meg on November 01, 2002 at 16:53:00:
: ok i took a test on trig n i dun get how i missed some of the questions... can u explain how to do them?
: 1). Given sin x=.8860 Find tan x correct to four decimal places. i got 1.664
Draw a right triangle. Make the hypotenuse = 1.
Make x one of the acute angles. Make the side opposite x = .8860. OK, now sin x = .8860, right?
So, what's the length of the other side? By the Pythagorean theorem: sqrt(1 - .88602)
So tan x = .8860/sqrt(1 - .88602)
tan x = 1.9108.
: 2). in right triangle, BCD, BD=12, the measure of angle C=90 and the measure of angle DBC=47. Find BC to the nearest tenth. i got 8.8
Draw the triangle. BD=12 is the hypotenuse. BC is the side adjacent to angle B (the 47-degree angle). So cos B = BC/BD or:
BC = 12 cos 47
BC = 8.7762
Post a Followup