CH 6 Use the quadratic formula to find all degree solutions

CH 6

Use the quadratic formula to find all degree solutions and theta if 0 degree lessthanorequalto theta

Solution

cos²+cos-1 =0

a)cos²+cos=1

cos²+cos+(1_/4)=1+(1_/4)

(cos+(1_/2))²=5_/4

(cos+(1_/2))=5_/2,(cos+(1_/2))=-5_/2

cos=(5 -1)_/2,cos=(-1-5)_/2

cos=(-1-5)_/2 => NO SOLUTION

cos=(5 -1)_/2

=>=360^ok -51.8^o,=360^ok +51.8^o

b)=51.8^o,308.2^o