Question

Chapter 7, Section 7.2, Question 023 (a) Find an angle e, with 0° <@ < 360°, that has the same cosine as 61° (but is not 61'). O= (b) Find an angle e, with 0* <@ < 360°, that has the same sine as 61' (but is not 61'). O= Click if you would like to Show Work for this question: Open Show Work SHOW HINT LINK TO TEXT Question Attempts: 0 of 3 used SAVE FOR LATER powered by MapleNet

Answer 1

(a) We know cosine is positive in quadrant first and fourth.

Hence cos(360°- theeta)= cos(theeta).

Hence cos(360°- 61°)=cos(61°)

Now question is

cos(61°)=cos(360°- 61°)=cos(299°)

Hence cos(61°)=cos(299°)

Therefore Theeta = 299°

(b)sine is positive in quadrant first and second.

Hence sin(180°- theeta)= sin(theeta)

Hence sin(180° - 61°)= sin(61°)

Now question is

sin(61°)=sin(180°- 61°)=sin(119°)

Hence sin(61°)=sin(119°)

Hence Theeta = 119°