What is the answer for question 8) ? http://postimg.org/image/yzcviz60z/

Asked on by lkballer24

1 Answer | Add Yours

llltkl's profile pic

llltkl | College Teacher | (Level 3) Valedictorian

Posted on

a) Given `costheta=1/sqrt10`

Therefore, `sintheta=sqrt(1-cos^2theta)`



`=3/sqrt10 ` (Note that if theta is a first quadrant angle, then the value of sintheta must be positive, so the negative root is discarded).

b) Given `tanbeta=-sqrt5/2`

Therefore, `secbeta=sqrt(1+tan^2beta)`



`=-3/2` (Note that if beta is a second quadrant angle, then the value of cosbeta, and secbeta must be negative, so the positive root is discarded).

Hence `cosbeta=1/secbeta`



We’ve answered 319,807 questions. We can answer yours, too.

Ask a question