Question

I'm not sure what this is asking.. Name an interval over which the cosine value is positive and the sine value is positive.

Answer 1

http://www.trigonometry-help.net/img/trig-tables_clip_image018.gif

So \[<0\rightarrow \frac{ \pi }{ 2 }>\]

Answer 2

how did you get that answer? when it asks for interval...does it want a point?

Answer 3

It wants a sequence of points which we express as an interval i.e.,

" a set of real numbers with the property that any number that lies between two numbers in the set is also included in the set"

If you use the Trigonometry chart you'll see that between 0 and 90 degrees (which also is 0 rad and pi/2 rad) both sine and cosine is positive.