• May 18th 2006, 01:13 AM
melissa
given that cos0=1/2 and 0 is anacute angle find the value of sin0 using trigonometric
• May 18th 2006, 04:20 AM
topsquark
Quote:

Originally Posted by melissa
given that cos0=1/2 and 0 is anacute angle find the value of sin0 using trigonometric

$sin^2 \theta + cos^2 \theta = 1$

So
$sin \theta = \pm \sqrt{1- cos^2\theta}=\pm \sqrt{1-(1/2)^2}$

$= \pm \sqrt{1-1/4}=\pm \sqrt{3/4} = \pm \sqrt{3}/2$.

We know that theta is an acute angle, so it's in the first quadrant. Also, sine is positive in the first quadrant. Thus: $sin \theta= \sqrt{3}/2$.

-Dan