Re: i dun get it...

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

Follow Ups:

• Re: i dun get it...me dun think yer #2 is correct... Denis Borris 18:29:57 11/01/02 (2)
  • Re: i dun get it...me dun think yer #2 is correct... Joel 19:05:03 11/01/02 (1)
    • Re: i dun get it...me dun think yer #2 is correct... meg 23:38:05 11/03/02 (0)

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