<p>There are often questions in Barron's and Sparks' tests where you should change your calculator mode to radian.
Moreover, the result that you would get in normal mode is there, as a choice, which makes it confusing. :(</p>
<p>How can I tell when the questions needs calculation in normal or radian mode?</p>
<p>you use radians when in the question the angle is in radians rather than degrees. if the angle says 'pi' or a small number its in radians. Also, radians is usally labeled as 'x' rather than theta.</p>
<p>If you do the problem in degrees and your answer doesn't match up with the choices then switch to radians. :0 vice versa.</p>
<p>Usually you only have to deal with radians.</p>
<p>Remind me, do they even use degrees on the test?</p>
<p>Yep! This is one of the questions I got wrong only because I was in radian mode:
If x= 76˚, tanx cscx =
(A) 0.24
(B) 0.82
(C) 1.03
(D) 1.21
(E) 4.13
If one would use raidan, it would be D. The correct one is E though.(degree mode)</p>
<p>From the same test, here's just another one where you're supposed to use radians:
If tanx = 1.73, then (sinx)^2 =
(A) 0.22
(B) 0.34
(C) 0.75
(D) 0.86
(E) 1.73
The answer's C.</p>
<p>these two questions can be easily solved by just using degrees, you don't need to convert to radians.
Are there any other questions that need the use of radians in angle measurements ?</p>
<p>An example of a problem where it's better to use radians is finding arclength. The formula for arclength is r * theta, where r is the radius of the circle and theta is the central angle, in radians.
It's in Calculus class that radians become really critical.</p>
<p>I wouldn't think twice before using radians in arclength/sector questions. What's worrisome is a handful of questions in which one would have to decide whether to use radians or degrees.
Strangely enough I can't recall any now. :(
And ironically on the one I previously posted you can freely use radian or degree to get the same result.</p>
<p>Whatever the case, I certainly do remember missing a bunch of questions only because I was using degrees instead of radians and vice versa.</p>
<p>I was going to ask the same thing. There are problems in Barrons Math IIC that use radians when you're not supposed to. Or atleast I'm pretty sure you don't use radians. </p>
<p>Ex: Pg 108 for #9.</p>